EB Vacuum Environment Probing
There are two main probing applicaion in need for vacuum environment.
Cryogenics :
Because the wafer is probed at the cryogenics temperature,the moisture will
appear and freezeon the wafer.This moisture will result in the leakae as high
as to make the measurement failure.The moisture in the chamber is removed
by the vacuum pump.The pump has to be kept running all the measurement
long.
High Temp. Oxygen-Free:
When the wafer is heated up more than 300 degree C ,400 degree C,500 degree C and higher,oxidation will occur greatly.The higher the temperature,the more greatly it oxidize on the wafer surface.The oxidation will make the wafer degrade electrically,physically & mechanically.The oxygen in the chamber is removed by the vacuum pump.The pump has to be kept running all the measurement long.
Because the chuck will be controlled thermally for the application both for
cryogenics and high temperature,the probed tip on the wafer will shift somewhat
by the wafer shrinkage and expansion.As a result,some of the tips have to be re-positioned by the micropositioner with the control knobs X-Y-Z put ouside the vacuum chamber.
Alternatively,the motorized micropositioner with the joystick control panel outside can re-positioned the tip in the chamber easily.
