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US3615929A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming epitaxial region of predetermined thickness and article of manufacture

Assignee: Texas Instruments Inc
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Filing: 1965-07-08
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Granted: 1971-10-26
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Expires: 1985-07-08
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Abstract

Abstract A process is disclosed for fabricating semiconductor devices in which a patterned oxide film of a predetermined thickness is formed on a semiconductor substrate followed by epitaxially forming on exposed areas of the substrate a layer of semiconductor material having a preselected thickness relative to the thickness of the oxide layer.

Inventors

  • 👤 William M Portnoy
  • 👤 Warren P Waters
  • 👤 Emery C Wisman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 17:43
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/101; H10D84/121; H10D84/60; H10D84/611; H10D84/613; H10D84/617; H10D99/00; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/026; Y10S148/043; Y10S148/085

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 19 words
The method of claim 1 wherein said oxide deposition is optically monitored, and said epitaxial deposition is mechanically monitored.
Claim 2
Dependent Claim 15 words
The method of claim 1 wherein said oxide layer is thermally formed over said substrate.
Claim 3
Dependent Claim 19 words
The method of claim 1 wherein said one conductivity of said semiconductor substrate and said semiconductor plug is N-type.
Claim 4
Dependent Claim 50 words
The method of claim 1 wherein said first oxide layer is thermally formed over said substrate, and said second oxide layer is formed by a low-temperature process to minimize diffusion of said semiconductor plug from said substrate and to minimize concentration of impurities in said semiconductor plug along its surface.
Claim 5
Independent Claim 325 words
A method of fabricating a semiconductor device of the type that includes a metal-semiconductor diode, comprising the steps of: a. forming an elongated low-resistivity diffused region within a high-resistivity semiconductor substrate; b. forming a first oxide layer over at least one surface of said substrate; c. monitoring the formation of said first oxide layer and adjusting the parameters of the oxide-forming process to produce a preselected thickness; d. photolithographically defining and removing a selected area of said first oxide layer to expose an elongated area of said diffused region and to produce an oxide band that circumscribes the exposed elongated area of said diffused region; e. epitaxially depositing a high-resistivity semiconductor material over the exposed area of said diffused region to a thickness substantially equal to the thickness of said oxide band to produce an elongated plug of said semiconductor material, said thickness of said elongated plug being substantially equal to or less than the depletion width of the semiconductor material thereof; f. monitoring the epitaxial deposition of said elongated plug relative to the thickness of said oxide band and adjusting the parameters of the epitaxial deposition process to produce said elongated plug having said preselected thickness; g. forming a second oxide layer over said elongated plug and oxide band; h. photolithographically defining and removing a selected area of said second oxide layer to expose the surface area of said elongated plug; i. photolithographically defining and removing selected areas of said first and second oxide layers to selectively expose said diffused region; j. depositing a nonalloying metallized film over said second oxide layer to form a rectifying contact with said elongated plug and to form an ohmic contact with said latter exposed areas of said diffused region; and k. selectively removing portions of said nonalloying metallized film to form a first conductive strip extending into selective contact with said diffused region and to form a second conductive strip extending into contact with said elongated plug.
Claim 6
Independent Claim 378 words
A method of fabricating a semiconductor device of the type that includes a metal-semiconductor diode, comprising the steps of: a. diffusing first and second spaced regions of one conductivity type into a monocrystalline semiconductor substrate of opposite conductivity type, said first and second spaced regions having impurity concentrations suitable for a collector region; b. diffusing a base region of said opposite conductivity type into said first diffused region; c. diffusing a third region of said one conductivity type into said base region and diffusing a fourth region of said one conductivity type into said second region, said third and fourth regions having an impurity concentration suitable for use as an emitter region; d. forming a first oxide layer over the surface of said substrate; e. monitoring the formation of said first oxide layer and adjusting the parameters of the oxide-forming process to produce a preselected thickness; f. photolithographically defining and removing a selected area of said first oXide layer to expose an area of said second region to produce an oxide band circumscribing said exposed area of said second region; g. epitaxially depositing a high-resistivity semiconductor material over said exposed area of said second region to a thickness substantially equal to the thickness of said oxide band to produce a semiconductor plug, said thickness of said semiconductor plug being substantially equal to or less than the depletion width of the semiconductor material therein; h. monitoring the epitaxial deposition of said semiconductor plug relative to the thickness of said oxide band and adjusting the parameters of the epitaxial deposition process to produce said semiconductor plug having said preselected thickness; i. forming a second oxide layer over said oxide band and semiconductor plug; and j. photolithographically defining and removing selected areas of said second oxide layer to expose said semiconductor plug, and to remove selected areas of said first and second oxide layers to expose said first, third, fourth and base regions; k. selectively depositing a nonalloying metallized film over said substrate to make rectifying contact with said semiconductor plug to form said metal-semiconductor diode, and to make ohmic contact with said first, third, fourth and base regions; and l. selectively removing said nonalloying metallized film to form separated strip conductors respectively contacting said semiconductor plug and said active regions.
Claim 7
Independent Claim 289 words
A method of fabricating a semiconductor device comprising the steps of: a. forming a first oxide layer over at least one surface of a monocrystalline semiconductor substrate of one conductivity type having an impurity concentration suitable for use as a collector region of a transistor; b. monitoring the formation of said first oxide layer and adjusting the parameters of the oxide-forming process to produce a preselected thickness; c. photolithographically defining and removing selected areas of said first oxide layer to expose at least one geometrically shaped area of said substrate and to produce a geometrically shaped band of said first oxide layer that circumscribes said geometrically shaped area; d. epitaxially depositing a semiconductor material of opposite conductivity type with an impurity concentration suitable for use as the base region of a transistor within said geometrically shaped area to a thickness substantially equal to the thickness of said geometrically shaped band to produce a semiconductor plug, said thickness of said semiconductor plug being substantially equal to or less than the depletion width of the semiconductor material thereof; e. monitoring the epitaxial deposition of said semiconductor plug relative to the thickness of said geometrically shaped band and adjusting the parameters of the epitaxial deposition process to produce said semiconductor plug having said preselected thickness; f. forming an emitter region of said one conductivity type within said semiconductor plug; g. forming a second oxide layer over said semiconductor plug; h. photolithographically defining and removing a selected area of said second oxide to expose a selected area of said emitter region and a selected area of said semiconductor plug; and i. selectively depositing a nonalloying metallized film over said exposed areas of said semiconductor plug and emitter region to form electrical contact therewith.
Claim 8
Independent Claim 309 words
A method of fabricating a semiconductor device of the type that includes a metal-semiconductor diode, comprising the steps of: a. forming a planar-type transistor device by successively diffusing a base region of one conductivity type and an emitter region of opposite conductivity type into a monocrystalline substrate of said opposite conductivity type serving as a collector region; b. forming a first oxide layer over said substrate; c. monitoring the formation of said first oxide layer and adjusting the parameters oF the oxide-forming process to produce a preselected thickness; d. photolithographically defining and removing a selected area of said first oxide layer to expose a selected area of said base region to produce an oxide band that circumscribes the exposed area of said base region; e. epitaxially depositing a high resistivity semiconductor material over the exposed area of said base region to a thickness substantially equal to the thickness of said oxide band to produce a semiconductor plug, said thickness of said semiconductor plug being substantially equal to or less than the depletion width of the semiconductor material thereof; f. monitoring the epitaxial deposition of said semiconductor plug relative to the thickness of said oxide band and adjusting the parameters of the epitaxial deposition process to produce said semiconductor plug having said preselected thickness; g. forming a second oxide layer over said semiconductor plug and said oxide band; h. photolithographically defining and removing a selected area of said second oxide layer to expose said semiconductor plug; i. photolithographically defining and removing selected areas of said first and second oxide layers to expose said base and emitter regions; and j. selectively depositing a nonalloying metallized film over the exposed areas of said semiconductor plug and said base and emitter regions to form a rectifying contact with said semiconductor plug and to form an ohmic contact with said base and emitter regions.
Claim 9
Independent Claim 331 words
A method of fabricating a semiconductor device of the type that includes a metal-semiconductor diode, comprising the steps of: a. diffusing a first region of one conductivity type into low-resistivity monocrystalline semiconductor substrate of opposite conductivity type; b. diffusing a second region of said one conductivity type into said first region, said second region having a lower resistivity than said first region; c. forming a first oxide layer over the surface of said substrate; d. monitoring the formation of said first oxide layer and adjusting the parameters of the oxide-forming process to produce a preselected thickness; e. photolithographically defining and removing a selected area of said first oxide layer to expose an area of said first region to produce an oxide band circumscribing said exposed area of said first region; f. epitaxially depositing a high-resistivity semiconductor material over said exposed area of said first region to a thickness substantially equal to the thickness of said oxide band to produce a semiconductor plug, said thickness of said semiconductor plug being substantially equal to or less than the depletion width of the semiconductor material therein; g. monitoring the epitaxial deposition of said semiconductor plug relative to the thickness of said oxide band and adjusting the parameters of the epitaxial deposition process to produce said semiconductor plug having said preselected thickness; h. forming a second oxide layer over said oxide band and semiconductor plug; i. photolithographically defining and removing selected areas of said second oxide layer to expose said semiconductor plug, and to remove a selected area of said first and second oxide layers to expose said second region; j. selectively depositing a nonalloying metallized film over said substrate to make rectifying contact with said semiconductor plug to form the anode of said metal-semiconductor diode, and to make ohmic contact with said second region to form the cathode of said metal-semiconductor diode; and k. selectively removing said nonalloying metallized film to form separate strip conductors respectively contacting said semiconductor plug and said second region.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-10-25 1975-04-26 1975-10-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-10-25 1979-04-26 1979-10-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-10-25 1983-04-26 1983-10-26 $7700.00 Window Closed / Lapsed

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