Method for monitoring the boron content of borophosphosilicate
US5441893A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1994 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Apr 4, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/22
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for monitoring the boron content of the borophosphosilicate, BPSG. The BPSG is obtained by the oxidation of silane, of diborane and of phosphine in a reactor, starting with a first, diborane/silane gas mixture and a second, phosphine/silane gas mixture by monitoring the ratio .rho.=diborane/(diborane+silane) of the mixture resulting from the mixing of the first and second gas mixtures. Monitoring of the boron content is obtained by measuring the density of the first mixture, determining the amount of residual hydrogen in the first mixture and modulating the mass flow rate of the first mixture in response to the calculated ratio .rho..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.