Patent · US Expired

Field-effect semiconductor device

US5404032A · kind A · utility

16Cited by
3References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 20, 1993
Grant dateApr 4, 1995
Priority date
Expiry dateAug 20, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10D62/221

Abstract

A novel field-effect semiconductor device having both low-noise and high-output operating characteristics has a first semiconductor buffer layer, an undoped second semi-conductor layer, an undoped third semiconductor layer the forbidden band gap of which increases from the substrate to the electrode side, a fourth semiconductor layer of one conductivity type, and a fifth semiconductor layer of undoped type or one conductivity type, formed one on top of another in this order on a semiconductor substrate. When the gate potential is deep, electrons mostly travel through the undoped second and third semiconductor layers, the device exhibiting superior low-noise characteristic; when the gate potential is shallow, electrons mostly travel through the highly doped fourth semiconductor layer, the device thus achieving high output characteristic.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.