EP0379208A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method for producing a device having an insulator sandwiched between two semiconductor layers
Assignee: Fujitsu Ltd
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Filing: 1990-01-19
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Granted: —
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Expires: 2010-01-19
Abstract
Abstract With the method for producing EPROMs based on self-alignment using a gate electrode as the mask for impurity ion doping, when selectively removing an oxide film between the control gate electrode and the floating gate electrode, the side surface of control gate electrode can be formed flat without projected and recessed areas by removing a thin film deposited at random on the side surface of the upper control gate electrode. Thus, the desired channel region width can be formed, even when impurity ions are doped, with the gate electrode used as the self-alignment mask. Controllability of EPROM production can, therefore, be remarkably improved.
Inventors
- 👤 Shunichi Nagata
- 👤 Tatsuya Mise
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:41
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0411; H10B; H10B69/00; H10D64/00; H10D64/01; H10D64/031; H10D64/035
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
174 words
A process for producing a device having an insulator sandwiched between two conductor layers, the process comprising the steps of: (a) forming a mask on the surface of a second conductor layer, said second conductor layer is formed on a multi-layer structure of a conductor substrate, a first insulating layer, a first conductor layer, and a second insulating layer in order; (b) removing the second conductor layer selectively using the mask until exposing a surface of the second insulating layer, and forming a second electrode; (c) removing the exposed second insulating layer selectively using the second electrode as a mask, and exposing the first conductor layer; (d) removing a thin film which is already deposited on a side surface of the second electrode formed in step (b); (e) removing the exposed first conductor layer selectively using the second electrode as a mask, and forming a first electrode; (f) removing the mask; and (g) doping an impurity ion in the conductor substrate using the second electrode as a mask, and forming an impurity doped region.
Claim 2
Dependent Claim
174 words
A process for producing a device having an insulator sandwiched between two conductor layers, the process comprising the steps of: (a) forming a mask on the surface of a second conductor layer, said second conductor layer is formed on a multi-layer structure of a conductor substrate, a first insulating layer, a first conductor layer, and a second insulating layer in order; (b) removing the second conductor layer selectively using the mask until exposing a surface of the second insulating layer, and forming a second electrode; (c) removing the exposed second insulating layer selectively using the second electrode as a mask, and exposing the first conductor layer; (d) removing a thin film which is already deposited on a side surface of the second electrode formed in step (b); (e) removing the exposed first conductor layer selectively using the second electrode as a mask, and forming a first electrode; (f) removing the mask; and (g) doping an impurity ion in the conductor substrate using the second electrode as a mask, and forming an impurity doped region.
Claim 3
Dependent Claim
23 words
A process as set forth in claim 1, wherein at least one of said first and second conductor layers comprise a semiconductor layer.
Claim 4
Dependent Claim
32 words
A process as set forth in Claim 1, wherein a way of selectively removing said first insulating layer or said first conductor layer or said second insulating layer is an anisotropic etching.
Claim 5
Dependent Claim
36 words
A process as in the steps (b), (c), (e) of Claim 1, wherein a way of selectively removing said first insulating layer or said first conductor layer or said second insulating layer is reactive ion etching.
Claim 6
Dependent Claim
23 words
A process as in Claim 3 wherein the reaction is carried out with a gas mixture containing sulfur hexafluoride supplied to a reactor.
Claim 7
Dependent Claim
24 words
A process as in the steps (d) of Claim 1 wherein a way of removing the thin film is by using a sputter etching.
Claim 8
Dependent Claim
26 words
A process as in the steps (d) of Claim 1 wherein a way of removing the thin film is etching with a solution containing hydroflouric acid.
Claim 9
Dependent Claim
24 words
A process as in the step (d) of Claim 1, wherein a way of removing the thin film is by using a gaseous plasma.
Claim 10
Dependent Claim
51 words
A process as in Claim 1 wherein step (a) is replaced by a step of: forming the second conductor layer on a surface of the second insulating layer, which is already formed on a Silicon On Insulator substrate, and next forming the mask on the surface of the second conductor layer.
Claim 11
Dependent Claim
37 words
A process as claimed in Claim 1, further comprising the step of: between step (e) and step (g); etching the projected insulator, which is raised on the side of the first and second electrodes, in a solution.
Claim 12
Dependent Claim
12 words
A process as in claim 1 wherein said mask is a photoresist.
Claim 13
Dependent Claim
35 words
A process as in Claim 1, wherein said second insulating layer comprises a layer formed with a material selected from a group of silicon oxide (SiO₂), silicon nitride (Si₃N₄) and SiO x N y .
References Cited (Backward Citations)
No citation records indexed.
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