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Browse Prior Art Database

Semiconductor Structure with High and Low Voltage Sections

IP.com Disclosure Number: IPCOM000050636D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 48K

Publishing Venue

IBM

Related People

Goins, EW: AUTHOR

Abstract

High and low voltage sections are provided on a single semiconductor chip or substrate by using a process which includes the formation of two epitaxial layers on the substrate.

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Semiconductor Structure with High and Low Voltage Sections

High and low voltage sections are provided on a single semiconductor chip or substrate by using a process which includes the formation of two epitaxial layers on the substrate.

As illustrated in Fig. 1, a first N+ diffusion region 10 and a first P+ diffusion region 12 are formed at the surface of a silicon substrate 14 having P type conductivity. A first epitaxial layer 16 having N type conductivity is grown over silicon substrate 14. While growing epitaxial layer 16, by outdiffusion from diffusion region 10 a first subcollector region 18 and by outdiffusion from diffusion region 12 a first segment 20 of an isolation region are formed between substrate 14 and epitaxial layer 16, as indicated in Fig. 2. Second and third N+ diffusion regions 22 and 24 and a second P+ diffusion region 26 are formed at the surface of first epitaxial layer 16. Region 22 is aligned over one end of subcollector 18, and region 26 is aligned over segment 20 and between regions 22 and 24.

As shown in Fig. 3, a second epitaxial layer 28, also having N type conductivity, is grown over first epitaxial layer 16. While growing epitaxial layer 28, by outdiffusion from diffusion region 24 a second subcollector region 30, by outdiffusion from diffusion region 26 a second segment 32 of the isolation region and by outdiffusion from diffusion region 22 a first segment 34 of a reach-through region are formed between first and second epitaxial layers 16 and 28. First segment 34 is arranged to contact subcollector region 18, and second segment 32 is arranged to contact first segment 20.

Fourth and fifth N+ diffusion regions 36 and 38 and a third P+ diffusion region 40 are formed at the surface of second epitaxial layer 28. Region 36 is aligned over first segment 34, region 40 is align...