Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

High Resistance Device Using Oxide Isolation Techniques

IP.com Disclosure Number: IPCOM000076862D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Jacobus, WN: AUTHOR

Abstract

This is a method of making dense high-value resistors in an isolation pocket, which method is fully compatible with advanced isolation technologies in integrated circuit processing.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

High Resistance Device Using Oxide Isolation Techniques

This is a method of making dense high-value resistors in an isolation pocket, which method is fully compatible with advanced isolation technologies in integrated circuit processing.

A P-type semiconductor body 10 has an N-type subcollector 11 formed therein and an elongated P-type region 12 formed in the N-type subcollector region. N-type epitaxial material 13 is then grown on the surface of body 10. During this epitaxial growth, both the N-type subcollector 11 and the P-type region 12 diffuse outwardly from the body 10 into the grown epitaxial material 13. Upon completion of the growth of the epitaxial material 13, a layer 14 of silicon dioxide is formed over the diffused P-type region 12. As this silicon dioxide layer 14 grows into the epitaxial layer 13, it reduces the thickness of the P-type region
12. As the thickness of the region 12 is reduced, its linear resistance between contact diffusions 15 and 16 increases.

When region 12 has a doping density of 10/17/ impurities per cubic centimeter and a thickness of 0.5 micron, a resistance of between 2 and 3 kilohms per square will be realized.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]