EP0199061A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Semiconductor devices
Assignee: TDK Micronas GmbH
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Filing: 1986-03-13
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Granted: —
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Expires: 2006-03-13
Abstract
Abstract A fully self-aligned polycrystalline silicon emitter bipolar transistor. Self-alignment of the p + base contact (12) is achieved by using oxidised sidewalls (8) - (sidewall spacers) of the emitter mesa (7) as part of the p + base contact implantation mask. Collector contact (13) alignment can be achieved using oxidised sidewalls (17) of polycrystalline silicon alignment mesas (14) defined in the same polysilicon as the emitter mesa (7) but deposited on oxide (2) rather than the implanted base region (5).
Inventors
- 👤 Peter Denis Scovell
- 👤 Peter Blomley
- 👤 Roger Leslie Baker
- 👤 Gary John Tomkins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 15:50
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/40; H10P76/408; H10P76/4085; Y; Y10; Y10S; Y10S148/00; Y10S148/01; Y10S148/011; Y10S148/124
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A method of manufacturing a bipolar transistor including the steps of defining a polycrystalline silicon emitter mesa on an unoxidised surface of a base region disposed in a semiconductor substrate, oxidising side walls of the mesa and the exposed unoxidised surface of the base region, and implanting a base contact region into the substrate in contact with the base region using at least one oxidised side wall of the mesa as part of the implantation mask whereby the base contact region is self-aligned with the emitter.
Claim 2
Independent Claim
86 words
A method of manufacturing a bipolar transistor including the steps of defining a polycrystalline silicon emitter mesa on an unoxidised surface of a base region disposed in a semiconductor substrate, oxidising side walls of the mesa and the exposed unoxidised surface of the base region, and implanting a base contact region into the substrate in contact with the base region using at least one oxidised side wall of the mesa as part of the implantation mask whereby the base contact region is self-aligned with the emitter.
Claim 3
Dependent Claim
41 words
A method as claimed in claim 1, wherein the base region is implanted into the substrate through an oxide layer disposed thereon via a window in a masking layer and wherein the oxide layer exposed by the window is subsequently removed.
Claim 4
Dependent Claim
34 words
A method as claimed in claim 2, wherein the mesa is defined from a layer of polycrystalline silicon deposited on the substrate subsequent to the removal of the oxide layer exposed by the window.
Claim 5
Dependent Claim
21 words
A method as claimed in claim 3, wherein the mesa definition comprises appropriately masking the polycrystalline silicon layer and dry etching.
Claim 6
Dependent Claim
93 words
A method as claimed in claim 3 or claim 4 further including the steps of defining at least one polycrystalline silicon contact alignment mesa from said layer of polycrystalline silicon, which alignment mesa is disposed on the oxide layer and the sidewalls of which alignment mesa are oxidised during said oxidising step, and implanting a collector contact region into the substrate using a least one oxidised sidewall of the alignment mesa as part of the implantation mask whereby the spacing between the emitter and the collector contact is defined by the alignment mesa.
Claim 7
Dependent Claim
39 words
A. bipolar transistor including a polycrystalline silicon emitter mesa in contact with a base region and including a base contact, the emitter having an oxidised sidewall which during manufacture of the transistor serves for self-alignment of the base contact.
Claim 8
Dependent Claim
39 words
A. bipolar transistor including a polycrystalline silicon emitter mesa in contact with a base region and including a base contact, the emitter having an oxidised sidewall which during manufacture of the transistor serves for self-alignment of the base contact.
Claim 9
Dependent Claim
48 words
A bipolar transistor as claimed in claim 6, wherein the emitter is disposed substantially centrally with respect to a surface of the base region and including two base contact regions disposed on opposite sides of the emitter and self aligned therewith by respective oxidised sidewalls of the emitter.
Claim 10
Dependent Claim
31 words
A bipolar transistor as claimed in claim 6 or claim 7, wherein the base region is disposed in surface region of a substrate and including a collector contact to the substrate.
Claim 11
Dependent Claim
32 words
A bipolar transistor as claimed in claim 8 and including a polycrystalline silicon alignment mesa spaced apart from the emitter mesa and defining the distance between the emitter and the collector contact.
References Cited (Backward Citations)
No citation records indexed.
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