Browse Prior Art Database

Electron Beam Control of FET Characteristics

IP.com Disclosure Number: IPCOM000095147D
Original Publication Date: 1965-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Speth, AJ: AUTHOR

Abstract

This technique is for varying the characteristics of an insulated-gate field effect transistor by low-energy electron beam irradiation.

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 99% of the total text.

Page 1 of 2

Electron Beam Control of FET Characteristics

This technique is for varying the characteristics of an insulated-gate field effect transistor by low-energy electron beam irradiation.

The NPN insulated-gate field effect transistor 1 in drawing A comprises spaced N-type source and drain diffusions 3 and 5 in a P-type wafer 7. Thin silicon dioxide (SiO(2)) layer 9, approximately 6000 angstroms, and an aluminum gate electrode 11, approximately 1500 angstroms, are formed over conduction channel 13. This is defined along the narrow surface portion of wafer 1 intermediate diffusions 3 and 5. While gate electrode 11 is biased positively with respect to wafer 7, transistor 1 is irradiated by a low-energy electron beam indicated by the arrow 15.

For each value of gate bias voltage V(GB) during exposure to beam 15 which is approximately 2 x 10/-5/ coul/cm/2/, the threshold voltage shifts to a stable value. The steady state transconductance G(m)-gate voltage V(G) characteristics of transistor 1 with a low source-drain voltage after exposure to electron beam 15 are illustrated in drawing B. As indicated, the threshold voltage shifts as a linear function of gate bias voltage V(GB). Similar effects are obtained when PNP insulated-gate field effect transistors are treated, as described. Effects due to the low-energy electron irradiation can be annealed out by heating transistor 1 at a temperature of 200 degrees C. for several hours.

1

Page 2 of 2

2

[This page contains 3 pictures o...