Fabrication Procedure for the SBSC
Structural details of an SBSC device such as the layered barrier metal, antireflection coating, (100) single-crystal p-type silicon layer, and aluminum contact are shown in Figure 5.6. The aluminum ohmic contact must be first formed prior to the deposition of the barrier metal layer. The layered barrier metal consists of a chromium layer of about 50 A thick adjacent to silicon to provide the proper photovoltaic effect. A copper layer with 50- to 70-A thickness is deposited over the chromium layer to provide low sheet resistance. A silicon oxide layer of 690 A (0.069 pm or 69 nm) thick is deposited to produce an excellent antireflection coating for the device. The metal-silicon oxide system on a sliding glass permits light transmission efficiency better than 55.6 percent at a wavelength of 0.6 pm .