Patent ID: 6121102
Filing Date: 2000-09-19
Classification: H01L

Abstract:
A method of manufacturing a bipolar device at the surface of a semi-conducting plate, comprising the steps of:producing an inner layer having a high electrical conductivity,producing active layers for forming at least one active region, all of an active region extending above the inner layer, and the inner layer forming an electrical connection to a first one of the active layers,producing electrically isolating trenches, which at least partly surround the active region,producing a hole in a trench down to the inner layer having a high conductivity by applying a mask layer having a window to the surface of the semi-conductor device, the window being located to cover at least part of a sidewall of an electrically isolating trench,etching through the window using an etching agent only attacking material of other than said active layers, including material in the electrically isolating trench, and above the active layers, but not material in the active region, andfilling the hole with an electrically conducting material, so that the electrically conducting material comes in electrical contact with the inner layer having a high conductivity, in order to form an electrical connection to the inner region.