Method of manufacturing a perforated workpiece
First Claim
1. A method for manufacturing a perforated workpiece having holes extending perpendicular to a first surface of the workpiece, which is of a material of n-doped, single-crystal silicon, said method comprising providing a substrate wafer of an n-doped, single-crystal silicon having the first surface, electrochemically etching the substrate to produce the structured layer by connecting the substrate as an anode, contacting the first surface of the substrate with an electrolyte, setting a current density which will influence the etching erosion, continuing the etching to form the holes extending to a desired depth and corresponding to the thickness of the finished workpiece, and then modifying the parameters of the etching process to cause an increased lateral etching to enlarge the cross section of the holes adjacent the base of the holes with this lateral etching, and subsequently stripping the structured layer of the workpiece as a lamina from the substrate wafer.
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Abstract
A method of forming holes extending perpendicular to a first surface of a workpiece comprises providing the substrate wafer of n-doped, single-crystal silicon, and then electrochemically etching the substrate wafer to form a structured layer having the desired perforations. The electrochemical etching particularly occurs in a fluoride-containing electrolyte, and the substrate wafer is connected as an electrode. If the process parameters are maintained, the electrochemical etching will produce holes having a constant, substantially uniform cross section. However, varying the process parameters can cause changes in the cross section of the hole adjacent a base of the hole so that it is possible to enlarge the hole to facilitate stripping the workpiece as a lamina from the substrate.
111 Citations
16 Claims
- 1. A method for manufacturing a perforated workpiece having holes extending perpendicular to a first surface of the workpiece, which is of a material of n-doped, single-crystal silicon, said method comprising providing a substrate wafer of an n-doped, single-crystal silicon having the first surface, electrochemically etching the substrate to produce the structured layer by connecting the substrate as an anode, contacting the first surface of the substrate with an electrolyte, setting a current density which will influence the etching erosion, continuing the etching to form the holes extending to a desired depth and corresponding to the thickness of the finished workpiece, and then modifying the parameters of the etching process to cause an increased lateral etching to enlarge the cross section of the holes adjacent the base of the holes with this lateral etching, and subsequently stripping the structured layer of the workpiece as a lamina from the substrate wafer.
Specification