Control of gas content in process liquids for improved megasonic cleaning of semiconductor wafers and microelectronics substrates
US5800626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1997 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Feb 18, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB08B2203/002
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An efficient cleaning process of microelectronics devices requires lower levels of megasonic power, lower temperature and much lower concentrations of chemicals. The method controls the effectiveness of megasonics-assisted cleaning of microelectronics devices by securing a gas concentration level in the cleaning solution, such that at the process temperature the solution is partially saturated with the gas. The gas concentration can be controlled either at the plant-wide level or, preferably, at the point of use. In the latter case, two water supply inputs are provided, one of vacuum-degassed water and the other of gas-saturated water. Process water in the desired gas concentration is then obtained by mixing water from the two sources in an appropriate ratio, which resulting mixture is fed to the wafer cleaning vessel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.