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US3607465A
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Method of manufacturing a semiconductor device comprising a zener diode and semiconductor device manufactured by said method
Assignee: US Philips Corp
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Filing: 1968-06-28
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Granted: 1971-09-21
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Expires: 1988-06-28
Abstract
Abstract A method of making in a monolithic integrated semiconductor circuit a Zener diode having a reverse breakdown voltage in the range of 2.5-6 volts is described. This is obtained by constructing one of the diode zones as a heavily doped buried layer and the other diode zone as a heavily doped surface layer and out-diffusing the former and in-diffusing the latter until they meet to form an abrupt junction having the desired characteristics. A heavily doped surface contact region is diffused down to the buried zone to make available a surface contact for the latter.
Inventors
- 👤 Jean-Claude Frouin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:02
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/60; H10D84/67; H10D84/673; H10D84/01; H10D84/0112; H10D84/02; H10D84/03; H10D84/038; H10D84/611; H10D84/613; H10D99/00; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/085; Y10S148/145; Y10S148/151; Y10S438/00; Y10S438/983
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
18 words
A method as set forth in claim 1 wherein the epitaxial layer is of the opposite type conductivity.
Claim 2
Dependent Claim
18 words
A method as set forth in claim 1 wherein the epitaxial layer is of the one type conductivity.
Claim 3
Dependent Claim
91 words
A method as set forth in claim 1 wherein the epitaxial layer comprises a first portion of one type conductivity on the substrate and a second portion of opposite type conductivity on the first epitaxial portion, the surface second zone and contact third zone are diffused into the surface of the second epitaxial portion, and the diffusions are such that the buried first zone has a thickness substantially the same thickness as the first epitaxial portion, and the surface second zone has substantially the same thickness as the second epitaxial portion.
Claim 4
Dependent Claim
22 words
A method as set forth in claim 1 wherein the contact third zone is annular and completely surrounds the surface second zone.
Claim 5
Dependent Claim
97 words
A method as set forth in claim 1 wherein the substrate part is of the one type conductivity, the epitaxial layer is of the opposite type conductivity, prior to prediffusing the first zone an isolation fourth zone of the opposite type conductivity is diffused into the substrate part and the first zone is then prediffused into the fourth zone which isolates the first zone from the substrate part of one type conductivity, and the Zener diode is isolated from the epitaxial layer by difFusing zones of one type conductivity through the epitaxial layer into the substrate part.
Claim 6
Independent Claim
319 words
A method of making a monolithic integrated semiconductor device containing a Zener diode, comprising the steps: a. providing a semiconductor substrate part of the one type conductivity; b. growing on the substrate part a first epitaxial layer of the opposite type conductivity; c. prediffusing into the surface of a portion of the first epitaxial layer a first zone of one type conductivity having an impurity concentration exceeding that of the substrate and the first epitaxial layer; d. growing on the first epitaxial layer portion a second epitaxial layer of the opposite type conductivity having an impurity concentration below that of said prediffused first zone to bury the latter; e. diffusing into a surface of second epitaxial layer overlying the buried first zone a surface second zone of the opposite type conductivity having an impurity concentration exceeding that of the epitaxial layers and applying heat to cause in-diffusion of the second zone and out-diffusion of the buried first zone and continuing the diffusion until the in-diffused front of the surface second zone reaches the out-diffused front of the buried first zone to form an abrupt junction; f. diffusing into the surface of the second epitaxial layer overlying the buried first zone a contact third zone of the one type conductivity until its diffusion front reaches the out-diffused front of the buried first zone to form a low resistance connection thereto; g. diffusing isolation regions of said one type conductivity through the first and second epitaxial layers to define an opposite type island surrounding the first, second and third zones; h. and making a connection to the surface of the second zone as one electrode and making a connection to the surface of the third zone as the other electrode of a Zener diode having a reverse breakdown voltage in the range between 2.5 and 6 volts determined by the high impurity gradients in the region of the said abrupt junction.
Claim 7
Independent Claim
312 words
A method of making a monolithic integrated semiconductor device containing a Zener diode, comprising the steps: a. providing a semiconductor substrate part of the one type conductivity; b. growing on the substrate part a first epitaxial layer of the opposite type conductivity; c. prediffusing into the surface of a portion of the first epitaxial layer a first zone of opposite type conductivity having an impurity concentration exceeding that of the substrate and the first epitaxial layer; d. growing on the first epitaxial layer portion a second epitaxial layer of the one type conductivity having an impurity concentration below that of said prediffused first zone to bury the latter; e. diffusing into a surface of second epitaxial layer overlying the buried first zone a surface second zone of the one type conductivity having an impurity concentration exceeding that of the epitaxial layers and applying heat to cause in-diffusion of the second zone and out-diffusion of the buried first zone and continuing the diffusion until the in-diffused front of the surface second zone reaches the out-diffused front of the buried first zone to form an abrupt junction; f. diffusing into the surface of the second epitaxial layer overlying the buried first zone a contact third zone of the opposite type conductivity until its diffusion front reaches the out-diffused front of the buried first zone to form a low resistance connection thereto; g. diffusing isolation regions through the first and second epitaxial layers to define an island surrounding the first, second and third zones; h. and making a connection to the surface of the second zone as one electrode and making a connection to the surface of the third zone as the other electrode of a Zener diode having a reverse breakdown voltage in the range between 2.5 and 6 volts determined by the high impurity gradienTs in the region of the said abrupt junction.
Claim 8
Independent Claim
329 words
A method of making a monolithic integrated semiconductor device containing a Zener diode, comprising the steps: a. providing a semiconductor substrate part; b. growing on the substrate part a first epitaxial layer of the one type conductivity; c. prediffusing into the surface of a portion of the first epitaxial layer a first zone of opposite type conductivity and a second zone of the one type conductivity both having an impurity concentration exceeding that of the substrate and the first epitaxial layer; d. growing on the first epitaxial layer portion a second epitaxial layer of the one type conductivity having an impurity concentration below that of said prediffused first and second zones to bury the latter; e. diffusing into a surface of second epitaxial layer overlying the buried first zone a surface third zone of the opposite type conductivity having an impurity concentration exceeding that of the epitaxial layers and applying heat to cause in-diffusion of the third zone and out-diffusion of the buried second zone and continuing the diffusion until the in-diffused front of the surface third zone reaches the out-diffused front of the buried second zone to form an abrupt junction; f. diffusing into the surface of the second epitaxial layer overlying the buried second zone a contact fourth zone of the one type conductivity until its diffusion front reaches the out-diffused front of the buried second zone to form a low resistance connection thereto; g. diffusing isolation regions of said opposite type conductivity through the second epitaxial layer to define with the buried first zone an opposite type island surrounding the second, third and fourth zones; h. and making a connection to the surface of the third zone as one electrode and making a connection to the surface of the fourth zone as the other electrode of a Zener diode having a reverse breakdown voltage in the range between 2.5 and 6 volts determined by the high impurity gradients in the region of the said abrupt junction.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |