Aqueous hydrofluoric and hydrochloric acid vapor processing of semiconductor wafers
US5238500A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1990 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | May 21, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/26
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Disclosed are methods and apparatuses for combined etching and cleaning of semiconductor wafers and the like preferably using hydrofluoric acid (HF), hydrochloric acid (HCl) and water solutions which generate equilibrium vapor mixtures of HF vapor, HCl vapor and water vapor as a homogenous processing gas. The processing gases do not employ a carrier gas which will make the vapors nonhomogeneous and reduce etching rates. The vapors are preferably generated from a liquid source which is provided within a contained reaction chamber which holds the wafer. The wafer is preferably oriented with the surface being processed directed downward. The wafer is advantageously positioned above or in close proximity to the liquid source of the processing vapor. The wafer is rotated at a rotational speed in the range of 20-1000 revolutions per minute to provide uniform dispersion of the homogeneous processing gas across the wafer surface and to facilitate circulation and transfer from the liquid source into processing gas and onto the processed surface. The liquid source of the vapor can advantageously be provided in a bath immediately below the processed surface of the wafer or in toroidal basin a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.