Compound Semiconductor


Photolithography is a key process in semiconductors, but it's not ideal for microcircuit fabircation with certain metals. For cirtical process such as III-V group, II-VI group or MEMS, the most commonly used metal is chromium. Unlike aluminum, chrimium is not easy to be etched. In this kind of situation, we need to use lift-off process. Below is the simplified illustration for lift-off process. 

  • The key to high yields in lift-off process ilies in step 4. In this very step, it's extremely critical to deposit metal thin film perpendicularly & uniformly onto the wafer sruface.

  • If the metal thin film fails to be deposited perpendicularly, the side wall of photoresist will be deposited with metal. This will makes it impossible to remove photoresist with acetone and cause defects in device.

  • If the metal thin film fails to be deposited uniformly unto the wafer surface, it will cause defects in device as well.

 

For industrial applications, large wafer size will pose great challenge to deposit metal thin film perpendicularly & uniformly, as larger wafer size tends to incur poor uniformity. However Temescal has a solution to this. Temescal is an US-based company dedicated in e-beam evaporation technology and provides following industry-proven solutions to sovle this dilemma.