Browse Prior Art Database

GaAs Variable FET Width Gate Array using an Isolation Implant

IP.com Disclosure Number: IPCOM000108577D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 141K

Publishing Venue

IBM

Related People

Anderson, CJ: AUTHOR [+3]

Abstract

This article describes how to make a gate array using FETs with the flexibility to alter the FET after they have been fabricated.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

GaAs Variable FET Width Gate Array using an Isolation Implant

       This article describes how to make a gate array using
FETs with the flexibility to alter the FET after they have been
fabricated.

      Gate arrays or master slices are efficient for the
manufacturing of logic chips.  The wafers for gate arrays are
processed up through the transistors and resistors. These wafers can
now be characterized and stock-piled.  The different logic functions
on the gate arrays are created by personalizing only the wiring on
the chip.  Gate arrays allow for the fast implementation of designs
because only the wiring is different on each chip and the starting
point for fabricating new circuit designs is on wafers that have the
transistors and resistors already completed.  Gate array circuits
using bipolar transistors and resistors can be customized efficiently
because the bipolar transistors are all one size and the value of the
resistors can be varied by the wiring on the chip.  The ability to
set the resistor values in the personalization of the wiring allows
for the designer to optimize the function, speed, and power of the
bipolar circuits.  Gate array circuits using FETs are hard to
customize efficiently because the width of the FETs cannot be changed
by the wiring on the chip. Different-width FETs are required to
optimize FET circuits with respect to function, speed, power, and
area.  The FET gate arrays do not have the versatility that bipolar
transistor gate arrays have.

      This article describes an application of an isolation implant
to fabricate variable-width...