Fabrication methods for T-gate and inverted L-gate structure for high frequency devices and circuits
US8455312B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Sep 12, 2011 |
| Grant date | Jun 4, 2013 |
| Priority date | — |
| Expiry date | Sep 12, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/28593
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In high frequency circuits, the switching speed of devices is often limited by the series resistance and capacitance across the input terminals. To reduce the resistance and capacitance, the cross-section of input electrodes is made into a T-shape or inverted L-shape through lithography. The prior art method for the formation of cavities for T-gate or inverted L-gate is achieved through several steps using multiple photomasks. Often, two or even three different photoresists with different sensitivity are required. In one embodiment of the present invention, an optical lithography method for the formation of T-gate or inverted L-gate structures using only one photomask is disclosed. In another embodiment, the structure for the T-gate or inverted L-gate is formed using the same type of photoresist material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.