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
Iron golf club head
Circuit switched fallback for mobile terminated calls
System for access to and exchange of market data
Glycerol-containing functional fluid
Display control apparatus and display control method
Vapor-phase growth method for semiconductor film
Hand-held printing device and method for tuning ink jet color for printing on colored paper
  Randomly Featured Patents
Food battering machine
Moving picture coding method, and moving picture decoding method
Culturing embryonic stem cells, embryonic stem-like cells, or induced pluripotent stem cells with a Muc1 or Muc1* ligand
Furnace for manufacturing high calorific gas and coke from coal
Azeotropic compositions containing perfluorinated cycloaminoether
Walking toy figure
Methods for improving the residual control of mites and prolonging the protection of plants from mites infestations
Protective means for a lifting/tilting or tilting device
Automatic soap dispensing device
User interface apparatus for displaying vocal or instrumental unit signals in an input musical tone signal