Browse Prior Art Database

Electrically Alterable Resistors

IP.com Disclosure Number: IPCOM000048179D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Abbas, SA: AUTHOR [+3]

Abstract

Electrically alterable resistors are known to be useful in applications like programmable read only storage, programmable logic arrays and redundancy in random access memories. There is a processing need for them in today's and future bipolar/MOSFET technologies.

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Electrically Alterable Resistors

Electrically alterable resistors are known to be useful in applications like programmable read only storage, programmable logic arrays and redundancy in random access memories. There is a processing need for them in today's and future bipolar/MOSFET technologies.

Suitable resistors can be formed in the bipolar and other technologies, as shown in Fig. 1. Using a mask, preferably after first level metal pattern 9 has been formed with ohmic contacts 8 to device elements, a small window is opened in the silicon nitride layer 10 over the resistor 11. The silicon dioxide layer 12 may also be partially thinned, if desired, but this is not preferred.

With the photoresist mask (not shown) still in place silicon, hydrogen, boron, argon or other suitable ions are implanted through the silicon dioxide layer 12 in the window to create a narrow region A of damage into the body of the P resistor
11. The resistance value of the resistor increases substantially because of this damage.

The resistor can be switched to a lower resistance state by electrically generating heat in or near the damaged region A. This is done either by passing current through the resistor itself or through the neighboring P-N junction formed between the P resistor and the N subcollector 13/epitaxial layer 14. In the latter case the subcollectors, B, can be tied to a separate "word" line with individual (selected) resistors, R, as the "bit" lines, using the existing decoder...