Focused ion beam visual endpointing
US6838294B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2002 |
| Grant date | Jan 4, 2005 |
| Priority date | — |
| Expiry date | Nov 21, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3151
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for use in removing a portion of a semiconductor chip. The method comprises etching a backside of the semiconductor chip, the frontside including a first well with a first type of doping and a second well with a second type of doping; monitoring a backside of the semiconductor chip during etching; and determining when a first portion of the backside over one of the first and second wells differs from a second portion of the backside over the other of the first and second wells. A method for etch endpoint detection includes etching a backside of a semiconductor chip, the semiconductor chip having at least one doped well formed proximate a frontside of the semiconductor chip; monitoring the backside of the semiconductor chip during etching until at least one doped well becomes visible; and stopping etching after the doped well becoming visible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.