Controlling Wafer Temperature During Sputter Etching to Control Etch Uniformity
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
The temperature of wafers is monitored by an infrared detector while the wafers are being etched. The etch rate is adjusted in order to maintain the desired temperature to provide uniform etch distribution. In the DC sputter etching of semiconductor wafers the etch rate increases exponentially as the wafer temperature is increased. Conventional techniques to control wafer temperature during etching include varying the current or maintaining a constant voltage in the sputter etch power supply, etching for a fixed period of time, and maintaining a constant cooling gas pressure and flow. In the present technique, the wafer temperature is measured and the voltage of the sputter power supply is adjusted in order to vary the etch rate to maintain the wafer temperature at a desired level.