Substrates
Phasis gold thin films are grown on high grade muscovite mica sheets freshly cleaved. The quality of the mica is classified from V-1 to V-10 according to the ASTM international standard. V-1 is considered as the best quality. It is a visual system of classifying the quality of natural muscovite mica based upon relative amounts of visible foreign inclusion. At Phasis we are using muscovite mica with quality higher of equal to V-2. The mica sheets are cleaved just before their introduction into the deposition system. The thickness of the final cleaved mica sheets may vary from 0.080mm to 0.130mm. The mica cleaving process is of random nature and the final thickness of the mica sheets cannot be controlled with better accuracy.
Gold size and thickness
Phasis offers the gold films in various geometries and sizes. The largest gold deposited region is 2 cm x 2 cm and the smallest 4 mm x 4 mm. The complete list of available geometries can be found under products.
Cutting a gold thin film grown on mica into smaller parts degrades the gold surface. Mica is indeed a very hard material and thus difficult to cut. With the different proposed geometries, the cutting process becomes easier because it can be done in-between the gold areas without damaging the gold surface. It is thus possible to maximise the number of possible measurements. Do not hesitate to contact us if you have a request for a special gold geometry not proposed in our list.
The typical gold thickness we provide is 200 nm. With our experience, we know that 200 nm thick films present good surface quality. We can grow thinner of thicker films upon request. For very thin film however, the gold surface will present islands with holes in-between, the film being not thick enough to allow a better covering.