A Micromachined Titanium Sputter Ion Pump for Cavity Pressure Control

This paper describes a micro-scale sputter ion pump and its use in the controlled reduction of pressure in a large cavity package. The pump is composed of titanium electrodes on a glass substrate which are sputtered away and form the source of Ti ions that react and bind with oxygen and nitrogen. The discharges are powered by DC and pulsed DC high voltage. The duration of applied voltage determines the amount of sputtered titanium and consequently, the pressure reduction inside a cavity. To date, the pressure inside sealed commercial packages of volumes 6.33 cm³and 2.2 cm³, has been reduced by 168 Torr and 126 Torr, respectively.