Patent ID: 8008209
Filing Date: 2011-08-30
Classification: H01L,Y10S

Abstract:
1. A method of forming high aspect ratio structures in a semiconductor wafer, comprising the steps of: selecting a temperature sensitive reaction such that the reaction rate thereof is significantly higher at a first reaction temperature than at a second reaction temperature; controlling the temperature in the interior of a semiconductor wafer to be close to a first predetermined temperature; controlling the temperature of an upper surface of the semiconductor to be close to a second predetermined temperature; performing the selected reaction on the wafer such that the reaction proceeds at a different rate near the upper surface of the wafer near the second predetermined temperature than in the interior of the wafer near the first predetermined temperature; wherein the step of controlling the temperature in the interior of a semiconductor wafer comprises the steps of: selecting a laser wavelength to which the surface of the wafer is substantially transparent and which is easily absorbed by materials in the interior of the wafer; and applying pulsed laser energy at the selected wavelength to the wafer to produce localized heating in the interior of the wafer.