Resources Contact Us Home
Heterojunction bipolar transistor and method of producing the same

Image Number 7 for United States Patent #6924201.

A heterojunction bipolar transistor of the present invention is produced from a wafer including a substrate and a collector layer of a first conductivity type, a base layer of a second conductivity type and an emitter layer of the first conductivity type sequentially laminated on the substrate in this order. First, the wafer is etched up to a preselected depth of the collector layer via a first photoresist, which is formed at a preselected position on the emitter layer, serving as a mask. Subsequently, the collector layer etched with at least the sidewalls of the base layer and collector layer, which are exposed by the first etching step, and a second photoresist covering part of the surface of the collector layer contiguous with the sidewalls serving as a mask.

  Recently Added Patents
Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same
Representing polarized light in computer models
Therapeutic rinse in a self-heating package
Detection of procedural deficiency across multiple business applications
Perception-based artifact quantification for volume rendering
Communication apparatus, communication method, and communication system
White light emitting diode (LED) lighting device
  Randomly Featured Patents
Pharmaceutical compositions
Method and apparatus of supporting production of application program layout and a computer program product
Sanitary toilet seat cover
Image pickup apparatus having lens array and image pickup optical system
Rail cap
Preparation of homopolymers and copolymers of .alpha.-monoolefins using a Ziegler catalyst system
Vehicular lamp
Audio signal transforming by utilizing a computational cost function
Devices for conversion between serial and parallel data
Combined annular ice skate blade and hub