US3909304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of doping a semiconductor body
Assignee: AT&T Inc
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Filing: 1974-05-03
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Granted: 1975-09-30
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Expires: 1994-05-03
Abstract
Abstract A doped region is formed in a semiconductor body by implanting ions of dopant atoms into a surface layer of the body and then selectively etching a portion of the implanted surface layer to delineate the desired region. If a buried region is desired, an epitaxial layer is grown over both etched and unetched portions of the implanted surface layer. Before the epitaxial layer is grown, the implanted ions can be diffused farther into the semiconductor body.
Inventors
- 👤 Kon Ho Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:46
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/60; H10D84/67; H10D84/673; H10P; H10P95/00; H10W; H10W15/00; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/017; Y10S148/037; Y10S148/051; Y10S148/085; Y10S148/145; Y10S148/151; Y10S438/00; Y10S438/914; Y10S438/92
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
63 words
A METHOD OF FORMING A DOPED REGION INA SEMOCONDUCTOR BODY WHICH COMPRISES: IMPLANTING IONS OF DOPANT ATOMS INTO A SURFACE OF THE SEMICONDUCTOR TO FORM AN IMPLANTED SURFACE LAYER SELECTIVELY COATING SAID IMPLANTED SURFACE WITH AN ATCHRESISTANT PATTERN CORRESPONDING O THE DESIRED DOPED REGION, AND ETCHING THE UNCOATED PORTION OF SAID COATED SURFACE TO A DEPTH WHERE SUBSTANTALLY ALL IMPLANTED IONS ARE REMOVED
Claim 2
Independent Claim
63 words
A METHOD OF FORMING A DOPED REGION INA SEMOCONDUCTOR BODY WHICH COMPRISES: IMPLANTING IONS OF DOPANT ATOMS INTO A SURFACE OF THE SEMICONDUCTOR TO FORM AN IMPLANTED SURFACE LAYER SELECTIVELY COATING SAID IMPLANTED SURFACE WITH AN ATCHRESISTANT PATTERN CORRESPONDING O THE DESIRED DOPED REGION, AND ETCHING THE UNCOATED PORTION OF SAID COATED SURFACE TO A DEPTH WHERE SUBSTANTALLY ALL IMPLANTED IONS ARE REMOVED
Claim 3
Dependent Claim
32 words
The method of claim 1 which further comprises: removing the etch-resistant pattern, and growing a continuous epitaxial layer on said semiconductor surface having the doped region to form a buried doped region.
Claim 4
Dependent Claim
23 words
The method of claim 2, which further comprises: before the epitaxial layer growing step, diffusing said implanted ions farther into the semiconductor body.
Claim 5
Dependent Claim
132 words
In a method of forming a buried doped region in a semiconductor body, comprising the steps of forming a surface layer of fopant atoms in the semiconductor, selectively etching away a portion of the surface layer to delineate the doped region, and diffusing the remaining dopant atoms farther into the semiconductor, the improvement which comprises: in the forming step, implanting ions of the dopant atoms into a surface of the semiconductor body to form the surface layer of dopant atoms; in the selective etching step, etching away the portion of the surface layer to a depth where substantially all implanted ions are removed to leave the resulting etched surface substantially free from defects; and after the diffusing step, growing a continuous epitaxial layer on said semiconductor surface having the delineated doped region.
Claim 6
Dependent Claim
132 words
In a method of forming a buried doped region in a semiconductor body, comprising the steps of forming a surface layer of fopant atoms in the semiconductor, selectively etching away a portion of the surface layer to delineate the doped region, and diffusing the remaining dopant atoms farther into the semiconductor, the improvement which comprises: in the forming step, implanting ions of the dopant atoms into a surface of the semiconductor body to form the surface layer of dopant atoms; in the selective etching step, etching away the portion of the surface layer to a depth where substantially all implanted ions are removed to leave the resulting etched surface substantially free from defects; and after the diffusing step, growing a continuous epitaxial layer on said semiconductor surface having the delineated doped region.
Claim 7
Dependent Claim
91 words
In a method of forming a buried doped region in a semiconductor body comprising the steps of forming a layer of implanted ions of dopant atoms in the semiconductor and growing an epitaxial layer on at least the implanted ion layer, the improvement which comprises: in the forming step, implanting the ions into a surface layer of the semiconductor; and selectively etching the surface layer to a depth where substantially all implanted ions are removed to leave the resulting etched surface substantially free from defects and to delineate the doped region.
Claim 8
Dependent Claim
91 words
In a method of forming a buried doped region in a semiconductor body comprising the steps of forming a layer of implanted ions of dopant atoms in the semiconductor and growing an epitaxial layer on at least the implanted ion layer, the improvement which comprises: in the forming step, implanting the ions into a surface layer of the semiconductor; and selectively etching the surface layer to a depth where substantially all implanted ions are removed to leave the resulting etched surface substantially free from defects and to delineate the doped region.
Claim 9
Dependent Claim
23 words
The method of claim 5 which further comprises: before the epitaxial layer growing step, diffusing the implanted ions farther into the semiconductor body.
Claim 10
Independent Claim
197 words
A method of forming buried doped regions in a semiconductor body, wherein a first doped region comprises atoms of a first conductivity type and a second doped region comprises atoms of a second conductivity type, comprising the steps of: implanting ions of dopanT atoms of the first conductivity type into a selected surface of the semiconductor to form a first implanted surface layer, selectively coating the selected surface with a first etch-resistant pattern corresponding to the desired first doped region, exposing the coated surface to an etchant to delineate the first doped region, removing the first etch-resistant pattern, diffusing the implanted ions farther into the body, implanting ions of dopant atoms of the second conductivity type into the selected surface of the semiconductor to form a second implanted surface layer, selectively coating the selected surface with a second etch-resistant pattern corresponding to the desired second doped region, exposing the coated surface to an etchant to delineate the second doped region, removing the second etch-resistant layer, diffusing the implanted ions farther into the body, and growing a continuous epitaxial layer on both a portion of the selected surface of the semiconductor and the first and second doped regions.
Claim 11
Independent Claim
197 words
A method of forming buried doped regions in a semiconductor body, wherein a first doped region comprises atoms of a first conductivity type and a second doped region comprises atoms of a second conductivity type, comprising the steps of: implanting ions of dopanT atoms of the first conductivity type into a selected surface of the semiconductor to form a first implanted surface layer, selectively coating the selected surface with a first etch-resistant pattern corresponding to the desired first doped region, exposing the coated surface to an etchant to delineate the first doped region, removing the first etch-resistant pattern, diffusing the implanted ions farther into the body, implanting ions of dopant atoms of the second conductivity type into the selected surface of the semiconductor to form a second implanted surface layer, selectively coating the selected surface with a second etch-resistant pattern corresponding to the desired second doped region, exposing the coated surface to an etchant to delineate the second doped region, removing the second etch-resistant layer, diffusing the implanted ions farther into the body, and growing a continuous epitaxial layer on both a portion of the selected surface of the semiconductor and the first and second doped regions.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |