RIE Damage Measuring Device
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Reactive ion etching (RIE) is desirable to use for etching contacts since it produces a small and well-controlled contact. However, RIE causes p contacts to become rectifying and the forward voltage on the Schottky barrier diode (SBD) to be lower. Diffusing or ion-implanting a p-type resistor in n-type material provides a means of detecting and measuring the amount of damage caused by RIE or ion-milling. Current is forced at, e.g., +1 ma, on metal pad 3 to ground on metal pad 4, and voltage is measured between pads 1 and 2. Then, about -1 ma current is forced from pad 3 to ground on pad 4. Voltage is again measured between pads 1 and 2. The amount of damage is a smoothly varying function of the ratios of the positive voltage and the negative voltage or the degree of the rectification.