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
Method and apparatus for secure transfer and playback of multimedia content
System for collecting computer application usage data of targeted application programs executed on a plurality of client devices
Solid-state image pickup element, method of manufacturing the same, and image pickup apparatus including the same
Container
Scoring records for sorting by user-specific weights based on relative importance
System and method for internet based procurement of goods and services
Relative pose estimation of non-overlapping cameras using the motion of subjects in the camera fields of view
  Randomly Featured Patents
X-ray CT apparatus
Expression of pace in host cells and methods of use thereof
Liquid crystal display device
Testing programmable logic arrays
Packaging of artificial eyelashes
System and method for determining elegibility and enrolling members in various programs
Ice fishing rig
Volume control
Method of bonding protective covers onto solar cells
Airless spray gun diffuser