Method for eliminating charging of photoresist on specimens during scanning electron microscope examination
US5783366A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1995 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Dec 7, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/38
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is described whereby a wafer having a layer of photoresist on its surface, can be subjected to ion implantation just prior to examination by a scanning-electron-microscope(SEM) thereby rendering the photoresist sufficiently conductive that charging of the surface does not occur within the SEM. Accumulation of surface charge on specimens in the SEM causes gross image distortion and obliteration. The technique is particularly useful for inspecting a developed photoresist layer on an insulating layer such as silicon oxide prior to oxide etching. Such is the case when the wafer is being inspected for photoresist quality and pattern dimensions prior to contact opening. The resist mask is developed and subjected to a low dosage ion implant. Images are rendered crisp and clear allowing for accurate measurements. The ability to test the photo pattern at this point is cost effective in that it permits the option of photoresist re-work, and lessens the need for a post-etch inspection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.