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

Electrically Trimmable Resistor Structure

IP.com Disclosure Number: IPCOM000048117D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Bergeron, DL: AUTHOR [+2]

Abstract

A diode resistor circuit arrangement is permits adjustment of the resistor value by electrically shorting diodes connected along the length of a diffused or ion implanted resistor in a semiconductor chip or substrate.

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 60% of the total text.

Page 1 of 2

Electrically Trimmable Resistor Structure

A diode resistor circuit arrangement is permits adjustment of the resistor value by electrically shorting diodes connected along the length of a diffused or ion implanted resistor in a semiconductor chip or substrate.

As illustrated im Fig. 1, the resistor 10 is a P+ diffused region having a plurality of Schottky barrier diodes (SBDs 12 formed adjacent to and along the length of resistor 10. Filaments 14 are formed between selected diodes 12 and spaced-apart contact points at an edge of the P+ diffused region resistor 10. A minimum spacing of four microns may be achieved between contact points. Trim tabs 16, provided by the SBD metal, as illustrated more clearly in Fig. 2, are internal to the chip in which the P+ diffused region resistor 10 is formed and are required to be isolated from each other during resistor programming. Diodes 18, having one terminal held high by an appropriate voltage at pad Y, are used for isolation purposes.

In Fig. 2, a preferred shorting arrangement is illustrated in a sectional view. Each of the Schottky barrier diodes 12 has a Schottky barrier diode metal 16 which is selectively shorted to an associated contact point on the P+ diffusion region resistor 10 by applying an appropriate voltage pulse between the SBD metal 16 and an N- epitaxial layer 20 to form conductive filaments 14. A filament 14 is produced, more specifically, by reverse biasing the SBD junction into deep avalanche, while main...