Patent US4663969A successfully refreshed from Google Patents.
Patent US5885904A successfully refreshed from Google Patents.
US5885904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method to incorporate, and a device having, oxide enhancement dopants using gas immersion laser doping (GILD) for selectively growing an oxide layer
Assignee: Lattice Semiconductor Corp
•
Filing: 1997-02-14
•
Granted: 1999-03-23
•
Expires: 2017-02-14
Abstract
Abstract A method for forming a uniform and reliable oxide layer on the surface of a semiconductor substrate using projection gas immersion laser doping (P-GILD) is provided. A semiconductor substrate is immersed in an oxide enhancing compound containing atmosphere. The oxide enhancing compound containing atmosphere may include phosphorus, arsenic, boron or an equivalent. A 308 nm excimer laser is then applied to a portion of the substrate to induce incorporation of the oxide enhancing compound into a portion of the substrate. The deposition depth is dependent upon the strength of the laser energy directed at the surface of the substrate. A uniform and reliable oxide layer is then formed on the surface of the substrate by heating the substrate. The laser may be applied with a reflective reticle or mask formed on the substrate. An E 2 PROM memory cell having a program junction region in a silicon substrate is also provided. An oxide layer is positioned between a program junction and a floating gate. The oxide layer is formed by a single or multiple thermal oxidation step(s) to have at least a first oxide thickness due to a GILD oxide enhancing compound underlying a region of the oxide having at least the first oxide thickness.
Inventors
- 👤 Sunil Mehta
- 👤 Emi Ishida
- 👤 Xiao-Yu Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:28
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6502; H10P14/6509; H10P14/6512; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; H10P50/73; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
52 words
A method for forming an oxide on the surface of a semiconductor substrate, comprising: placing the semiconductor substrate in an atmosphere containing an oxidation enhancing compound; applying laser energy to at least a first portion of the substrate; and forming the oxide on the surface of the substrate by heating the substrate.
Claim 2
Independent Claim
52 words
A method for forming an oxide on the surface of a semiconductor substrate, comprising: placing the semiconductor substrate in an atmosphere containing an oxidation enhancing compound; applying laser energy to at least a first portion of the substrate; and forming the oxide on the surface of the substrate by heating the substrate.
Claim 3
Dependent Claim
22 words
The method of claim 1, further comprising the step of: positioning a reflective reticle to pattern the laser over the semiconductor substrate.
Claim 4
Dependent Claim
17 words
The method of claim 1, further comprising the step of: forming a mask on the semiconductor substrate.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein the oxidation enhancing compound atmosphere includes phosphorus.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein the oxidation enhancing compound atmosphere includes arsenic.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein the oxidation enhancing compound atmosphere includes boron.
Claim 8
Independent Claim
115 words
A method for forming an oxide on the surface of a semiconductor substrate, comprising: immersing the semiconductor substrate in a phosphorus containing atmosphere; applying a laser to a portion of the substrate to induce incorporation of the phosphorus into the portion of the substrate to a depth dependent upon the strength of the laser energy directed at the surface of the substrate; and forming the oxide on the surface of the substrate by heating the substrate in an oxidizing ambient such that the portion of the oxide formed over the selected portion is formed at a different rate than a portion of the oxide formed over regions of the substrate not including the selected portion.
Claim 9
Independent Claim
115 words
A method for forming an oxide on the surface of a semiconductor substrate, comprising: immersing the semiconductor substrate in a phosphorus containing atmosphere; applying a laser to a portion of the substrate to induce incorporation of the phosphorus into the portion of the substrate to a depth dependent upon the strength of the laser energy directed at the surface of the substrate; and forming the oxide on the surface of the substrate by heating the substrate in an oxidizing ambient such that the portion of the oxide formed over the selected portion is formed at a different rate than a portion of the oxide formed over regions of the substrate not including the selected portion.
Claim 10
Dependent Claim
24 words
The method of claim 7, wherein the immersion step includes the step of positioning a reflective reticle to pattern the laser over the substrate.
Claim 11
Dependent Claim
26 words
The method of claim 7, wherein the method further comprises the step of applying the laser for a second time to eliminate damage caused by incorporation.
Claim 12
Dependent Claim
13 words
The method of claim 7, wherein the incorporation is through solid phase diffusion.
Claim 13
Dependent Claim
13 words
The method of claim 7, wherein the incorporation is through liquid phase diffusion.
Claim 14
Independent Claim
130 words
A method for forming an oxide on a semiconductor substrate, comprising the steps of: forming a mask layer on the surface of the semiconductor substrate; immersing the semiconductor substrate in an oxide enhancing compound containing atmosphere; applying a laser to a portion of the substrate to induce incorporation of the oxide enhancing compound into the portion of the substrate to a depth dependent upon the strength of the laser energy directed at the surface of the substrate; and forming the oxide on the surface of the substrate by heating the substrate in an oxidizing ambient such that the portion of the oxide formed over the selected portion is formed at a different rate than a portion of the oxide formed over regions of the substrate not including the selected portion.
Claim 15
Independent Claim
130 words
A method for forming an oxide on a semiconductor substrate, comprising the steps of: forming a mask layer on the surface of the semiconductor substrate; immersing the semiconductor substrate in an oxide enhancing compound containing atmosphere; applying a laser to a portion of the substrate to induce incorporation of the oxide enhancing compound into the portion of the substrate to a depth dependent upon the strength of the laser energy directed at the surface of the substrate; and forming the oxide on the surface of the substrate by heating the substrate in an oxidizing ambient such that the portion of the oxide formed over the selected portion is formed at a different rate than a portion of the oxide formed over regions of the substrate not including the selected portion.
Claim 16
Dependent Claim
20 words
The method of claim 12, wherein the immersion step includes the step of applying a reflective reticle to the substrate.
Claim 17
Dependent Claim
26 words
The method of claim 12 wherein the method further comprises the step of applying the laser for a second time to eliminate damage caused by incorporation.
Claim 18
Dependent Claim
13 words
The method of claim 12, wherein the deposition is through solid phase diffusion.
Claim 19
Dependent Claim
13 words
The method of claim 12, wherein the deposition is through liquid phase diffusion.
Claim 20
Dependent Claim
23 words
The method of claim 12, wherein the energy of the laser is between approximately 650 MJ/cm 2 and approximately 1.3 J/cm 2 .
Claim 21
Dependent Claim
21 words
The method of claim 12, wherein the energy of the laser for non-melt P-GILD is less than 650 mJ/cm 2 .
Claim 22
Dependent Claim
14 words
The method of claim 12, wherein the laser is a 308 nm excimer laser.
Claim 23
Independent Claim
53 words
A method for forming an oxide on the surface of a semiconductor substrate, the oxide having at least a first thickness and a second thickness, comprising the steps of: gas immersion laser doping a region of the substrate with material containing an oxidation enhancing compound; and heating the substrate in an oxygen atmosphere.
Claim 24
Independent Claim
53 words
A method for forming an oxide on the surface of a semiconductor substrate, the oxide having at least a first thickness and a second thickness, comprising the steps of: gas immersion laser doping a region of the substrate with material containing an oxidation enhancing compound; and heating the substrate in an oxygen atmosphere.
Claim 25
Dependent Claim
12 words
The method of claim 20, wherein the oxide enhancing compound includes phosphorus.
Claim 26
Dependent Claim
12 words
The method of claim 20, wherein the oxide enhancing compound includes arsenic.
Claim 27
Dependent Claim
12 words
The method of claim 20, wherein the oxide enhancing compound includes boron.
Claim 28
Dependent Claim
17 words
The method of claim 20, wherein the method further includes the step of: positioning a reflection reticle.
Claim 29
Dependent Claim
19 words
The method of claim 20, wherein the method further includes the step of: forming a mask on the substrate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-22 | 2002-09-21 | 2003-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-22 | 2006-09-21 | 2007-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-22 | 2010-09-21 | 2011-03-23 | $7700.00 | Window Closed / Lapsed |