Resources Contact Us Home
Manufacturing method of well region in coms intergrated circuit

Image Number 9 for United States Patent #5114868.

First, N-type channel stoppers are formed in an element formation region of a P-channel MOS transistor and in an element isolation region of the P-channel MOS transistor, of a CMOS transistor. After forming a field oxide film, an N well is formed in the element formation region of the P-channel MOS transistor. In spite of the fact that the dose of ions used for the formation of an N-type channel stopper is smaller than the dose of ions used for the formation of an N well, the surface concentration of the N-type impurity of the N-type channel stopper is higher than that of the N well. The N-type impurity concentration in the portion where the N-type channel stopper and the N well are brought into contact, becomes uniform. The variability in the threshold voltage of the P-channel MOS transistor, the threshold voltage of the P-channel parasitic MOS transistor, the junction breakdown voltage of the P.sup.+ diffused layer and the junction capacitance of the P.sup.+ diffused layer is reduced, so that the device obtained is suited for the submicron process.

  Recently Added Patents
Electronic devices with voice command and contextual data processing capabilities
Apparatus for touch screen avionic device
RPM Controlled Wind Power Generation System
Evolutionary clustering algorithm
Method for distributing advertisements to client devices using an obscured ad monitoring function
Method, preprocessor, speech recognition system, and program product for extracting target speech by removing noise
Network based technique for obtaining operator identifier for mobile devices
  Randomly Featured Patents
Polymerization products containing amino groups useful in serum cholesterol level control
Fuel container support system for a combustion engine
Apparatus and method for measuring the breakdown voltage between two electrodes separated by a dielectric
Aquarium system
Biopsy and aspiration unit with a replaceable cannula
IC card
Film sheet for use in antiballistic articles
Circuit arrangement for generating non-overlapping clock phases
Engine speed control system for a working vehicle
Device in a circular, disk-shaped element intended for cleaning purposes