| 摘要 |
In a method of protecting a silicon PN junction the surface of the silicon slice is treated with sulphuric acid followed by oxidation of the silicon surface in a steam at about 1200 DEG C. and the cooling of the slice in an inert gas. In the method described silicon diodes, formed of mesa etched slices, are degreased in a suitable solvent which is then removed by a methyl alcohol rinse followed by boiling in nitric acid for 20 minutes at 100 DEG C., in turn followed by a deionized water rinse, the surface treatment being completed by immersion of the slices in concentrated sulphuric acid for twenty minutes at 1200 DEG C. Removal of most of the sulphate from the surface of the slice is performed by a water rinse followed by immersion in hydrofluoric acid, rinsing in water, further immersion in nitric acid before the slices are placed in a quartz boat and subjected to steam at atmospheric pressure for 5 1/2 hours, after which they are dried in helium for about an hour at 1200 DEG C., the oxidation temperature, then cooled in helium to room temperature. The oxide layer formed is about 20,000 </>rA thick. |
