US5698869A
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Insulated-gate transistor having narrow-bandgap-source
Assignee: Toshiba Corp
•
Filing: 1995-09-13
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Granted: 1997-12-16
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Expires: 2015-09-13
Abstract
Abstract A structure of a semiconductor device and a method of manufacturing the same is provided wherein a leakage current can be reduced while improving a drain breakdown voltage of an Insulated-Gate transistor such as a MOSFET, MOSSIT and a MISFET, and a holding characteristic of a memory cell such as a DRAM using these transistors as switching transistors can be improved, and further a reliability of a gate oxide film in a transfer gate can be improved. More particularly, a narrow band gap semiconductor region such as Si x Ge 1-x , Si x Sn 1-x , PbS is formed in an interior of a source region or a drain region in the SOI.IG-device. By selecting location and/or mole fraction of the narrow band gap semiconductor region in a SOI film, or selecting a kind of impurity element to compensate the crystal lattice mismatching due to the narrow-bandgap semiconductor region, the generation of crystal defects can be suppressed. Further the structure that the influences of the crystal defects to the transistor or memory characteristics such as the leakage current can be suppressed, even if the crystal defects are generated, are also proposed.
Inventors
- 👤 Makoto Yoshimi
- 👤 Satoshi Inaba
- 👤 Atsushi Murakoshi
- 👤 Mamoru Terauchi
- 👤 Naoyuki Shigyo
- 👤 Yoshiaki Matsushita
- 👤 Masami Aoki
- 👤 Takeshi Hamamoto
- 👤 Yutaka Ishibashi
- 👤 Tohru Ozaki
- 👤 Hitomi Kawaguchiya
- 👤 Kazuya Matsuzawa
- 👤 Osamu Arisumi
- 👤 Akira Nishiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:28
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/025; H10D30/60; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/05; H10B12/30; H10B12/31; H10D30/031; H10D30/0321; H10D30/0323; H10D30/67; H10D30/6704; H10D30/6713; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/013; H10D84/0144; H10D86/00; H10D86/201; H10P; H10P14/00; H10P14/40; H10P14/412; H10P30/00; H10P30/20; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P95/00; H10P95/90; H10D30/674; H10D30/675
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
134 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of at least a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region being doped with a first impurity element having the second conductivity type, and a second impurity element having a different covalent radius than that of the first impurity element so as to compensate a lattice mismatching in a heterojunction structure formed between said first and second semiconductors.
Claim 2
Dependent Claim
134 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of at least a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region being doped with a first impurity element having the second conductivity type, and a second impurity element having a different covalent radius than that of the first impurity element so as to compensate a lattice mismatching in a heterojunction structure formed between said first and second semiconductors.
Claim 3
Dependent Claim
27 words
A transistor as claimed in claim 1, wherein the second impurity element has a smaller covalent radius than that of a constituent element of said first semiconductor.
Claim 4
Dependent Claim
42 words
A transistor as claimed in claim 1, wherein said first semiconductor is Si, said second semiconductor is Si x Ge i-x , said first impurity element is one of As and Sb, said second impurity element is one of P and B.
Claim 5
Dependent Claim
23 words
A transistor as claimed in claim 1, wherein said first impurity is doped into different location than that of said second impurity element.
Claim 6
Dependent Claim
35 words
A transistor as claimed in claim 1, wherein said first semiconductor is Si, said second semiconductor is Si x Ge 1-x , said first impurity element is P and said second impurity element is B.
Claim 7
Dependent Claim
42 words
A transistor as claimed in claim 2, wherein said first semiconductor is Si, said second semiconductor is Si x Ge 1-x , said first impurity element is one of As and Sb, said second impurity element is one of P and B.
Claim 8
Dependent Claim
166 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region being doped with a first impurity element having the second conductivity type and a second impurity element having a different covalent radius than that of the first impurity element so as to compensate a lattice mismatching in a heterostructure formed between said first and second semiconductor; and a second conductivity type second source region formed adjacent to said first source region and formed of said first semiconductor, wherein at least the first impurity element is doped in said second source region.
Claim 9
Dependent Claim
166 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region being doped with a first impurity element having the second conductivity type and a second impurity element having a different covalent radius than that of the first impurity element so as to compensate a lattice mismatching in a heterostructure formed between said first and second semiconductor; and a second conductivity type second source region formed adjacent to said first source region and formed of said first semiconductor, wherein at least the first impurity element is doped in said second source region.
Claim 10
Dependent Claim
27 words
A transistor as claimed in claim 7, wherein the second impurity element has a smaller covalent radius than that of a constituent element of said first semiconductor.
Claim 11
Dependent Claim
53 words
A transistor as claimed in claim 7, wherein said first semiconductor is Si, said second semiconductor is Si x Ge 1-x , said first impurity element is As or Sb for said second impurity element of P or B, or said first impurity element is P for said second impurity element of B.
Claim 12
Dependent Claim
23 words
A transistor as claimed in claim 7, wherein said first impurity is doped into different location than that of said second impurity element.
Claim 13
Dependent Claim
35 words
A transistor as claimed in claim 7, wherein said first semiconductor is Si, said second semiconductor is Si x Ge 1-x , said first impurity element is P and said second impurity element is B.
Claim 14
Dependent Claim
172 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, said first conductivity type channel region formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; and a second conductivity type second source region formed adjacently on said second conductivity type first source region and formed of said first semiconductor, wherein a top surface of said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 15
Dependent Claim
172 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor, said first conductivity type channel region formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; and a second conductivity type second source region formed adjacently on said second conductivity type first source region and formed of said first semiconductor, wherein a top surface of said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 16
Dependent Claim
187 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed adjacently on said second conductivity type first source region and formed of said first semiconductor; and a source metal electrode formed on said second conductivity type first source region via a groove formed in said second conductivity type second source region, wherein said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 17
Dependent Claim
187 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed adjacently on said second conductivity type first source region and formed of said first semiconductor; and a source metal electrode formed on said second conductivity type first source region via a groove formed in said second conductivity type second source region, wherein said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 18
Dependent Claim
189 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed adjacently on said first source region and formed of said first semiconductor; a third source region formed on and contacted to said first source region and formed of a semiconductor which has a smaller forbidden band gap than that of said first semiconductor; and a source metal formed on said third source region, wherein said first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 19
Dependent Claim
189 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed adjacently on said first source region and formed of said first semiconductor; a third source region formed on and contacted to said first source region and formed of a semiconductor which has a smaller forbidden band gap than that of said first semiconductor; and a source metal formed on said third source region, wherein said first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition.
Claim 20
Dependent Claim
186 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film and a top of said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition; a refractory metal silicide film formed on and contacted to said second conductivity type first source region; and a source metal electrode formed on said refractory metal silicide film.
Claim 21
Dependent Claim
186 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film and a top of said second conductivity type first source region is formed at a location having a larger depth than that of a depletion layer depth at a minimum depth portion, the depletion layer depth extending from the second insulating film with a maximum gate voltage applied on the gate electrode at an operation condition; a refractory metal silicide film formed on and contacted to said second conductivity type first source region; and a source metal electrode formed on said refractory metal silicide film.
Claim 22
Dependent Claim
142 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on and in contact with a first insulating film, a second insulating film formed on the first body region, and a gate electrode formed on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed of the first semiconductor; and a first conductivity type second body region formed of the second semiconductor, wherein a portion of said first body region through which the main current of the transistor flows and the first source region are connected via said second body region.
Claim 23
Dependent Claim
142 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on and in contact with a first insulating film, a second insulating film formed on the first body region, and a gate electrode formed on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region formed of the first semiconductor; and a first conductivity type second body region formed of the second semiconductor, wherein a portion of said first body region through which the main current of the transistor flows and the first source region are connected via said second body region.
Claim 24
Dependent Claim
44 words
A transistor as claimed in claim 16, wherein said first source region has at least a portion which is located lower than that of said second source region, so that the bottom of the first source region is contacted to said first insulating film.
Claim 25
Dependent Claim
36 words
A transistor as claimed in claim 16, wherein said second source region is contacted to said first body region via at least one of an upper and a lower layer portions of said first body region.
Claim 26
Dependent Claim
39 words
A transistor as claimed in claim 16, wherein said second source region is not metallurgically contacted to said first body region, but electrically connected via said first source region and said second body region to said first body region.
Claim 27
Dependent Claim
22 words
A transistor as in claim 16, further comprising a metal silicide film being formed on and contacted to said first source region.
Claim 28
Dependent Claim
172 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the first body region, and a gate electrode on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region is formed on and in contact with said first insulating film; a second conductivity type second source region formed of the first semiconductor, the second source region is formed in contact with said first source region and in a location shallower than said first source region; and a first conductivity type second body region formed in contact with said first insulating film, wherein a lower layer portion of said first body region is electrically connected to said first source region via said second body region.
Claim 29
Dependent Claim
172 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the first body region, and a gate electrode on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the first source region is formed on and in contact with said first insulating film; a second conductivity type second source region formed of the first semiconductor, the second source region is formed in contact with said first source region and in a location shallower than said first source region; and a first conductivity type second body region formed in contact with said first insulating film, wherein a lower layer portion of said first body region is electrically connected to said first source region via said second body region.
Claim 30
Dependent Claim
22 words
A transistor as in claim 21, further comprising a metal silicide film being formed on and contacted to said first source region.
Claim 31
Dependent Claim
135 words
An Insulated-Gate transistor comprising: a first conductivity type first body region formed of a first semiconductor, which is formed on a first insulating film; a first conductivity type second body region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the second body region is formed on the first body region; a second insulating film formed on the second body region; a gate electrode on the second insulating film to control electric current flowing through said second body region; a second conductivity type first source region formed of the second semiconductor; and a second conductivity type second source region formed of the first semiconductor, the second source region is contacted to the first source region, wherein the first source region is contacted to said second body region.
Claim 32
Dependent Claim
135 words
An Insulated-Gate transistor comprising: a first conductivity type first body region formed of a first semiconductor, which is formed on a first insulating film; a first conductivity type second body region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor, the second body region is formed on the first body region; a second insulating film formed on the second body region; a gate electrode on the second insulating film to control electric current flowing through said second body region; a second conductivity type first source region formed of the second semiconductor; and a second conductivity type second source region formed of the first semiconductor, the second source region is contacted to the first source region, wherein the first source region is contacted to said second body region.
Claim 33
Dependent Claim
22 words
A transistor as in claim 23, further comprising a metal silicide film being formed on and contacted to said first source region.
Claim 34
Dependent Claim
240 words
An Insulated-Gate transistor having at least a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed by ion implantation method so as to provide a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region surrounding said second conductivity type first source region except at an upper surface thereof, said second conductivity type second source region formed of the first semiconductor; a second conductivity type drain region formed so that said first conductivity type channel region is sandwiched in between said second conductivity type second source region and said second conductivity type drain region; and crystal defects due to a lattice mismatching in a heterojunction between the first semiconductor and the second semiconductor, the crystal defects being selectively formed in the second conductivity type second source region at a portion just under edges of the gate electrode and confined in the second conductivity type second source region so that the crystal defects do not reach a pn junction interface formed between the first conductivity type channel region and the second conductivity type second source region.
Claim 35
Dependent Claim
240 words
An Insulated-Gate transistor having at least a first conductivity type channel region formed of a first semiconductor, which is formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed by ion implantation method so as to provide a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; a second conductivity type second source region surrounding said second conductivity type first source region except at an upper surface thereof, said second conductivity type second source region formed of the first semiconductor; a second conductivity type drain region formed so that said first conductivity type channel region is sandwiched in between said second conductivity type second source region and said second conductivity type drain region; and crystal defects due to a lattice mismatching in a heterojunction between the first semiconductor and the second semiconductor, the crystal defects being selectively formed in the second conductivity type second source region at a portion just under edges of the gate electrode and confined in the second conductivity type second source region so that the crystal defects do not reach a pn junction interface formed between the first conductivity type channel region and the second conductivity type second source region.
Claim 36
Dependent Claim
164 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film; a metal silicide film formed on and contacted to said second conductivity type first source region; a second conductivity type second source region formed adjacently to said second conductivity type first source region and to said metal silicide film, the second conductivity type second source region being formed of said first semiconductor; and a source metal electrode formed on said metal silicide film.
Claim 37
Dependent Claim
164 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film; a metal silicide film formed on and contacted to said second conductivity type first source region; a second conductivity type second source region formed adjacently to said second conductivity type first source region and to said metal silicide film, the second conductivity type second source region being formed of said first semiconductor; and a source metal electrode formed on said metal silicide film.
Claim 38
Dependent Claim
158 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film; a metal silicide film formed on and contacted to said second conductivity type first source region; and a source metal electrode formed on said metal silicide film, wherein an interface between said source metal electrode and said metal silicide film is disposed at a location deeper than a top surface of said first conductivity type channel region.
Claim 39
Dependent Claim
158 words
An Insulated-Gate transistor at least having a first conductivity type channel region formed of a first semiconductor formed on a first insulating film, a second insulating film formed on the first conductivity type channel region, and a gate electrode formed on the second insulating film to control electric current flowing through said first conductivity type channel region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden bandgap than that of said first semiconductor, a bottom of said second conductivity type first source region being contacted to said first insulating film; a metal silicide film formed on and contacted to said second conductivity type first source region; and a source metal electrode formed on said metal silicide film, wherein an interface between said source metal electrode and said metal silicide film is disposed at a location deeper than a top surface of said first conductivity type channel region.
Claim 40
Dependent Claim
130 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on and in contact with a first insulating film, a second insulating film formed on the first body region, and a gate electrode formed on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; and a first conductivity type second body region formed of the second semiconductor, wherein a portion of said first body region through which a main current of the transistor flows and the first source region are connected via said second body region.
Claim 41
Dependent Claim
130 words
An Insulated-Gate transistor having at least a first conductivity type first body region formed of a first semiconductor, which is formed on and in contact with a first insulating film, a second insulating film formed on the first body region, and a gate electrode formed on the second insulating film to control electric current flowing through said first body region, wherein the improvement comprises: a second conductivity type first source region formed of a second semiconductor having a narrower forbidden band gap than that of said first semiconductor; and a first conductivity type second body region formed of the second semiconductor, wherein a portion of said first body region through which a main current of the transistor flows and the first source region are connected via said second body region.
Claim 42
Dependent Claim
58 words
A transistor as claimed in claim 28, further comprising a second conductivity type second source region formed of the first semiconductor, wherein said first source region has at least a portion which is located deeper than that of said second source region, so that a bottom of the first source region is contacted to said first insulating film.
Claim 43
Dependent Claim
48 words
A transistor as claimed in claim 28, further comprising a second conductivity type second source region formed of the first semiconductor, wherein said second source region is contacted to said first body region via at least one of upper and lower layer portions of said first body region.
Claim 44
Dependent Claim
53 words
A transistor as claimed in claim 28, further comprising a second conductivity type second source region formed of the first semiconductor, wherein said second source region is not metallurgically connected to said first body region, but electrically connected via said first source region and said second body region to said first body region.
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