PECVD deposition of smooth silicon films
US9117668B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2012 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | Sep 19, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B43/27
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Smooth silicon films having low compressive stress and smooth tensile silicon films are deposited by plasma enhanced chemical vapor deposition (PECVD) using a process gas comprising a silicon-containing precursor (e.g., silane), argon, and a second gas, such as helium, hydrogen, or a combination of helium and hydrogen. Doped smooth silicon films and smooth silicon germanium films can be obtained by adding a source of dopant or a germanium-containing precursor to the process gas. In some embodiments dual frequency plasma comprising high frequency (HF) and low frequency (LF) components is used during deposition, resulting in improved film roughness. The films are characterized by roughness (Ra) of less than about 7 Å, such as less than about 5 Å as measured by atomic force microscopy (AFM), and a compressive stress of less than about 500 MPa in absolute value. In some embodiments smooth tensile silicon films are obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.