Field effect transistor
US7173292B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 2003 |
| Grant date | Feb 6, 2007 |
| Priority date | — |
| Expiry date | Jan 31, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/221
Abstract
In a field effect transistor having a quantum well is provided by a primary conduction channel, at least one secondary conduction channel immediately adjacent and in contact with the primary channel has an effect bandgap greater than the effective bandgap of the primary channel, and the modulus of the difference between the impact ionisation threshold IIT of the primary channel and the effective conduction band offset (the height of the step) between the primary and secondary channels being no more than 0.5 Eg (effective), or (alternatively) no more than 0.4 eV. Higher energy carriers which might otherwise cause impact ionization leading to runaway are thus diverted into the secondary channel allowing the device to run faster at increased voltages and/or to exhibit much greater resistance to runaway. The primary channel is prefereably of low bandgap material, for example InSb, InAs, InAs1-y, In1-xGaxAs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.