A test report is necessary to show the compliance between custom description and our final wafers data. We will test the wafer characerization by equipment before shipment, testing surface roughness by atomic force microscope, type by Roman spectra instrument, resistivity by non-contact resistivity testing equipment,micropipe density by polarizing microscope, orientation by X-ray Orientator etc. if the wafers meet the requirement, we will clean and pack them in 100 class clean room, if the wafers do not match the custom spec, we will take it off.
Testing Project: Surface roughness
Surface roughness is usually shortened to roughness and is a component of surface texture. It is quantified by the deviation of the normal vector direction of the real surface from its ideal form. If these deviations are large, the surface is rough; If they’re small, the surface is smooth. In surface measurement, roughness is generally considered to be the high frequency short-wave length component of measuring scale surface. In practice, however, it is often necessary to know the amplitude and frequency to ensure that the surface is suitable for a purpose.
Below is an example of surface roughness of GaN material:
A surface roughness-GaN