Patent ID: 6818564
Filing Date: 2004-11-16
Classification: B81B,B81C,H01L

Abstract:
A method for etching a bore into a silicon substrate from a first face thereof, the method comprising the steps of:forming a masking layer on the first face, patterning the masking layer to define an etch opening at a location corresponding to the location at which the bore is to be etched into the silicon substrate, subjecting the silicon substrate to a first dry etch in a controlled environment chamber through the etch opening for forming the bore to a first depth, the bore tapering inwardly from the first face to the first depth and defining a cone angle, the first dry etch being carried out using the Bosch process whereby the silicon substrate is sequentially subjected to alternating etch and deposition cycles through the etch opening, the duration of the respective etch and deposition cycles being controlled for controlling the cone angle defined by the bore extending between the first face and the first depth, andsubjecting the silicon substrate to a second dry etch in the controlled environment chamber through the etch opening on completion of the first etch for etching the bore to a second depth which is a greater distance from the first face than the distance of the first depth from the first face.