Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
System and method for content delivery
Satellite communication network
Ascertaining presentation format based on device primary control determination
Femtocell one-to-many packet delivery
Semiconductor device and method of manufacturing the same
Method for producing carrier on which microorganisms capable of conducting multiple parallel mineralization are immobilized, column reactor and solid medium for cultivating plants
Image forming apparatus
  Randomly Featured Patents
Sheet-material transporting device and automatic sheet-material feeder
System and process for treating waste water
Wavelength division multiplexing light transmitting system
Method and device for determining the duty-cycles of PWM control signals of an inverter
Method for highly sensitive hybridization of nucleic acids, and method for gene analysis using the same
Apparatus for synchronizing and allocating processes among several processors of a data processing system
Two word line SRAM cell with strong-side word line boost for write provided by weak-side word line
Laser seeker target simulator
Lock open and control system access apparatus for a downhole safety valve
System for measuring transmission bandwidth for media streaming and method for same