Shadow mask and method of fabricating vertically tapered structure using the shadow mask

Abstract

A method of fabricating a vertically tapered structure. The method includes placing a spacer layer at a predetermined area on a wafer, placing a mask layer at a predetermined area on the spacer layer, and over-etching the spacer layer, by etching a certain area below the mask layer, fabricating a cantilever type shadow mask having the spacer layer and the mask layer. Thus, it is possible to fabricate the vertically tapered structure of several tens of microns. The vertically tapered structure can be used as the optical waveguide in the optical device to minimize junction loss that may occur between the optical waveguide and the optical fiber.

1 . A shadow mask that etches a silicon layer on an SOI wafer at a predetermined pattern, the shadow mask comprising:
 a spacer layer placed on a predetermined area on the silicon layer; and   a mask layer having two regions of which one region at the lower surface adjoins the spacer layer and the other region is spaced apart from the silicon layer at a predetermined distance.   
   
   
       2 . The shadow mask according to  claim 1 , wherein the mask layer is made of at least one of aluminum, chromium, molybdenum, tungsten, manganese, titanium, nickel, copper, and zinc. 
   
   
       3 . The shadow mask according to  claim 1 , wherein the shadow mask consists only of the spacer layer and the mask layer.