Compound semiconductor device having an emitter contact structure including an I.sub.nx Ga.sub.1 -.sub.x As graded-composition layer
US5266818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1992 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Mar 17, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/62
Abstract
A compound semiconductor device wherein a contact to an n type Al.sub.x Ga.sub.1-x As layer comprises an In.sub.x Ga.sub.1-x As graded-composition layer, an In.sub.x Ga.sub.1-x As contact layer having a constant composition and a metal electrode layer, the In.sub.x Ga.sub.1-x As graded-composition layer is doped with an n type impurity which concentration is higher than a concentration of an impurity activated as n type, whereby, even when a thickness of the In.sub.x Ga.sub.1-x As graded-composition layer is made sufficiently small, a reduction in the carrier concentration of the thin graded-composition layer causes no increase of its resistance and a low-resistance contact is realized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.