Use of GaSb films as residual gas pressure monitors

Abstract

Thermally treated polycrystalline GaSb films with suitable geometries have been used as 'Pirani resistance gauges, to monitor the residual air pressure in a conventional demountable vacuum system. High sensitivity over a wide range of measurements (1.33 kPa-1.33 mPa (10-10-5 Torr)) has been obtained. The devices using CaF2 film protective covering showed considerable improvement in time stability over the unprotected devices. However, extensive studies on chemical passivation and electrostatic screening are necessary to eradicate the problem of long term stability, common to most thin film devices.