Patent ID: 9268089
Filing Date: 2016-02-23
CPC Classification: G02B,Y10T

Claim Text:
1. A method comprising: providing a first layer of a first material, wherein the first material etches at a first etch rate in a first etchant; providing an accelerator layer disposed on the first layer, the accelerator layer comprising a second material, wherein the second material etches at a second etch rate in the first etchant; providing a mask layer that is disposed on the accelerator layer, the mask layer comprising a field region and a shaped region that abuts the field region at a first end and extends from the field region along a first axis to a tip, the first axis being along a first lateral direction, the shaped region having opposing first and second sides that meet at the tip, wherein the first and second sides collectively define a first width along a second lateral direction that increases nonlinearly from the tip to the first end, the second lateral direction being orthogonal to the first lateral direction; laterally etching the accelerator layer in the first etchant such that the shaped region is undercut by a first lateral-etch front that proceeds normally inward from the first side and a second lateral-etch front that proceeds normally inward from the second side; and etching the first layer in the first region in the first etchant such that the thickness of the first layer increases nonlinearly from the tip to the first end.