Pattern of apertures in a showerhead for chemical vapor deposition
US6050506A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1998 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Feb 13, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C16/455
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A showerhead used for dispensing gas over a wafer in chemical vapor deposition (CVD), especially for CVD of metals. The patterns of holes is tailored to compensate for thermal and other effects, in particular by increasing the density of holes toward the periphery of the wafer in three or more zones. Such a variable pattern is particularly useful for liquid precursors that are atomized in a carrier gas, in which case a second perforated plate in back of the showerhead face can be eliminated, thereby reducing the flow impedance and the required pressure of the liquid-entrained gas, which tends to deposit out at higher pressures. The reduce flow impedance is particularly useful for CVD of copper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.