Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method and apparatus for detecting an endpoint polishing layer by transmitting infrared light signals through a semiconductor wafer










Image Number 4 for United States Patent #6074517.

An apparatus for polishing a first side of a semiconductor wafer down to a desired level includes a polishing platen having a polishing surface. The polishing platen has a light egress opening defined therein. The apparatus also includes a wafer carrier which is configured to engage the wafer by a second side of the wafer and apply pressure to the wafer in order to press the wafer against the polishing surface of the polishing platen, wherein the wafer carrier has a light-ingress opening defined therein. The apparatus further includes an infrared light source unit positioned such that light signals generated by the infrared light source unit are directed out the light egress opening and into the wafer. The apparatus yet further includes a light receiving unit positioned such that the light signals generated by the infrared light source unit emanate out of the wafer and are received with the light receiving unit. The light receiving unit includes a first optical material and a second optical material having an interface therebetween. The first optical material has a linear index of refraction, whereas the second optical material has a nonlinear index of refraction which is dependent on an intensity level of the light signals received with the light receiving unit. The light signals are refracted at the interface if the linear index of refraction of the first optical material does not match the nonlinear index of refraction of the second optical material. A method of polishing a first side of a semiconductor down to a desired level is also disclosed.








 
 
  Recently Added Patents
Plural component proportioner
Synchronous rectifier network unit circuit and method
Fluid intake and content management system
System and method of automatic piloting for in-flight refuelling of aircraft, and aircraft comprising said system
Integrated monitoring in problem management in service desk
Process for the preparation of protected L-alanine derivatives
Image processing apparatus, image registering method, program causing computer to execute image registering method, and recording medium in which program is recorded
  Randomly Featured Patents
Dispensing tube package
Pocket for crutches
Fuels
Syringe devices and methods for mixing and administering medication
Shoe
Apparatus and method for interference cancellation and synchronization maintenance over interference channel estimation in communication system based on full-duplex relay
Apparatus for controlling the movement of press components
Multi-stage high-performance amplifier
All plastic idler pulley assembly
Fixing device with improved heat control for use in an image forming apparatus