Verfahren zur Dotierung eines Halbleiters mittels Diffusion

摘要

1278565 Semi-conductor devices SIEMENS AG 14 July 1970 [15 July 1969] 34060/70 Heading H1K To form a doped region in the surface of a semi-conductor wafer a mixed oxide layer consisting of silicon dioxide and an oxide of a dopant element is deposited over the surface of the wafer and removed from over those areas where no doped region is required to be formed, the wafer and remaining mixed oxide layer being heated at 800‹ C. for 20 minutes in vacuo or in reducing atmosphere to cause diffusion of the dopant into the wafer surface. The unwanted areas of mixed oxide layer are removed by etching. Preferably the semi-conductor wafer has a surface with a 111, 110 or 100 crystal orientation on to which the mixed oxide layer is deposited. The process is described as applied to the fabrication of germanium PNP or NPN transistors.