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US5045488A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of manufacturing a single transistor non-volatile, electrically alterable semiconductor memory device

Assignee: Silicon Storage Technology Inc
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Filing: 1990-01-22
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Granted: 1991-09-03
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Expires: 2010-01-22
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Abstract

Abstract A methd of making an electrically programmable and erasable memory device having a re-crystallized floating gate is disclosed. A substrate is first defined. A first layer of dielectric material is grown over the substrate. A layer of polysilicon or amorphous silicon is then deposited over the first layer. The layer of silicon is covered with a protective material and is annealed to form recrystallized silicon. A portion of the protective material is removed to define a floating gate region. Making oxide is grown on the floating gate region. The remainder of the protective material and the recrystallized silicon thereunder is removed. A second layer of dielectric material is formed over the floating gate and over the substrate, immediately adjacent to the floating gate. A control gate is patterned and formed. Source and drain regions are then defined in the substrate.

Inventors

  • 👤 Bing Yeh

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 03:12
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/68; H10D30/6891; H10D30/681; H10D30/684; H10D30/685

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 124 words
A method of making an electrically programmable and erasable memory device comprising the steps of: defining a substrate; growing a first layer of dielectric material over said substrate; depositing a layer of polysilicon or amorphous silicon over said first layer; covering said layer of silicon with a protective material; annealing said layer of silicon to form. recrystallized silicon; removing a portion of said protective material to define a floating gate region; growing masking oxide on said floating gate region; removing the remainder of said protective material and the recrystallized silicon thereunder; depositing a second layer of dielectric material silicon dioxide over said floating gate and said substrate; patterning and forming a control gate; and defining a drain and a source region in said substrate.
Claim 2
Independent Claim 124 words
A method of making an electrically programmable and erasable memory device comprising the steps of: defining a substrate; growing a first layer of dielectric material over said substrate; depositing a layer of polysilicon or amorphous silicon over said first layer; covering said layer of silicon with a protective material; annealing said layer of silicon to form. recrystallized silicon; removing a portion of said protective material to define a floating gate region; growing masking oxide on said floating gate region; removing the remainder of said protective material and the recrystallized silicon thereunder; depositing a second layer of dielectric material silicon dioxide over said floating gate and said substrate; patterning and forming a control gate; and defining a drain and a source region in said substrate.
Claim 3
Dependent Claim 27 words
The method of claim 1, wherein said depositing said second layer step further comprises: performing nitridization of said silicon dioxide to form a layer of oxynitride film.
Claim 4
Dependent Claim 17 words
The method of claim 1, wherein said covering step further comprises: depositing a layer of silicon nitride.
Claim 5
Dependent Claim 52 words
The method of claim 1, wherein said removing a portion of said protective material further comprises: depositing a layer of photoresist; removing a portion of said photoresist to expose the protective material; removing the protective material with the remainder of the photoresist as the mask; and removing the remainder of the photoresist.
Claim 6
Dependent Claim 28 words
The method of claim 1 after the growing masking oxide step further comprising: removing a portion of the masking oxide; and implanting dopants into said floating gate region.
Claim 7
Independent Claim 184 words
A method of making a field isolation in a semiconductor integrated circuit device comprising the steps of: defining a substrate; growing a first layer of dielectric material over said substrate; depositing a first layer of polysilicon over said first layer of dielectric material; covering said first layer of polysilicon with a first protective layer; patterning and exposing an isolation region in said first protective layer with a masking material to form an exposed isolation region; removing the first protective layer, polysilicon layer from the exposed isolation region leaving a stack having sidewalls; removing the masking material; depositing a second protective layer; depositing a second polysilicon layer; removing the second polysilicon layer everywhere except around the sidewalls of the stack; converting the second polysilicon layer adjacent to said stack into silicon oxide spacer; implanting channel stop implant everywhere in the isolation region except where protected by the silicon oxide spacer; removing the second protective layer from areas not protected by the oxide spacer; removing the silicon oxide spacer; thermally growing field oxide adjacent said stack; and remove the remaining first protective layer and polysilicon layer.
Claim 8
Independent Claim 184 words
A method of making a field isolation in a semiconductor integrated circuit device comprising the steps of: defining a substrate; growing a first layer of dielectric material over said substrate; depositing a first layer of polysilicon over said first layer of dielectric material; covering said first layer of polysilicon with a first protective layer; patterning and exposing an isolation region in said first protective layer with a masking material to form an exposed isolation region; removing the first protective layer, polysilicon layer from the exposed isolation region leaving a stack having sidewalls; removing the masking material; depositing a second protective layer; depositing a second polysilicon layer; removing the second polysilicon layer everywhere except around the sidewalls of the stack; converting the second polysilicon layer adjacent to said stack into silicon oxide spacer; implanting channel stop implant everywhere in the isolation region except where protected by the silicon oxide spacer; removing the second protective layer from areas not protected by the oxide spacer; removing the silicon oxide spacer; thermally growing field oxide adjacent said stack; and remove the remaining first protective layer and polysilicon layer.
Claim 9
Dependent Claim 13 words
The method of claim 6, wherein said first protective layer is silicon nitride.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-02 1995-03-04 1995-09-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-02 1999-03-04 1999-09-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-02 2003-03-04 2003-09-03 $7700.00 Window Closed / Lapsed

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