A Germanium wafer is one of the most widely used semiconductors because of its exceptional crystallographic characteristics and rare electric features. Ge wafers are commonly used in sensors, infrared optics, and solar cell applications. But before a Ge wafer can be utilized in various sophisticated applications, it must go through the cleaning process to remove any contamination. If you want to know the cleaning process for germanium wafers, read on:
A Germanium wafer is cleaned through flowing deionized water and ingrained with HF. Then, a fine layer of oxide is prepared by submerging in a concoction of H2O2 and H2O. The oxide layer will then be removed by submerging in HF. Repeat these steps several times to guarantee the elimination of various atomic layers of Ge. Lastly, in an ultrahigh vacuum with temperatures ranging from 300-500°C, the oxide prepared will be thermally decomposed. Doing this allows sharp emission peaks to rise because of surface states in UPS showing a clean surface. This means that the oxygen and carbon present in the wafer is below the detection level.
You will know that a Ge wafer has been thoroughly cleaned if contaminants like oxygen and carbon cannot be detected by XPS and AES if the cross-sectional TEM analysis showed no flaw and if Germanium buffer tier growth and successive SiGe development showed a favorable structure and no buffer flaws.
Germanium wafer cleaning is important to ensure a successful high mobility integration of Germanium substrates. HF and HCI solutions are used to clean Germanium wafers because they do not destroy the GE substrate nor do they disintegrate the Germanium’s surface. But a concentrated HCI is more capable of getting rid of contaminants that contain an oxide or sub-oxide layer.
At Wafer World, all our wafers go through a series of cleaning processes to ensure quality. Get the high-quality Germanium wafer that you need at Wafer World. We’ve been serving the wafer industry for 20 years and we’ve gained satisfied clients from all over the world! Be one of them and call us today for inquiries or purchase wafers online!