Method for manufacturing SOI substrate
US7615456B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2008 |
| Grant date | Nov 10, 2009 |
| Priority date | — |
| Expiry date | Mar 25, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D86/00
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for manufacturing an SOI substrate superior in film thickness uniformity and resistivity uniformity in a substrate surface of a silicon layer having a film thickness reduced by an etch-back method is provided. After B ions is implanted into a front surface of a single-crystal Si substrate 10 to form a high-concentration boron added p layer 11 having a depth L in the outermost front surface, the single-crystal Si substrate 10 is appressed against a quartz substrate 20 to be bonded at a room temperature. Chemical etching is performed with respect to the single-crystal Si substrate 10 from a back surface thereof to set its thickness to L or below. A heat treatment is carried out with respect to an SOI substrate in a hydrogen containing atmosphere to outwardly diffuse B from the high-concentration boron added p layer 11, thereby acquiring a boron added p layer 12 having a desired resistance value. During this heat treatment, B in an Si crystal is diffused to the outside of the crystal in a state where it is coupled with hydrogen in the atmosphere, and a B concentration in the high-concentration boron added p layer 11 is reduced. In regard to a heat treatment temperature at thi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.