SEDL / STP / STP342-EB / STP44492S

Doping of Germanium Transistor Surfaces by Fluid-Base Encapsulant Systems

Borofsky, A. J.
Autonetics, Computer and Data Systems, Anaheim, Calif

Partridge, J.
Instrumentation Laboratory, Massachusetts Institute of TechnologySylvania Electrical Products, Inc., CambridgeWoburn, Mass.Mass.

Pages: 16    Published: Jan 1963

Download this paper for $25 PDF (308K)          View License Agreement
Abstract

Earlier observations of the sensitivity of some germanium transistor surfaces to the chemical nature of fluid-base encapsulant systems showed the need for the measurement and control of the properties of these systems. Volume resistivity, dielectric constant and dissipation factor measurements, and moisture content determinations by Karl Fischer titrations have been made on fluid-base encapsulants. The variation of properties within the two systems fluorochemical — colloidal silica — molecular sieve and silicone oil — alundum — molecular sieve are described.

Some relationships between the encapsulant properties and the distributions and stability of the surface-dependent electrical parameters (reverse saturation current, reverse leakage current, and current amplification factor) of germanium-alloy transistors have been determined. The need for adjustment of the encapsulant to account for changes in prior processing is illustrated by the introduction of ultrasonic cleaning of device surfaces before encapsulation.