Method of inspecting holes using charged-particle beam
US6787770B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 2002 |
| Grant date | Sep 7, 2004 |
| Priority date | — |
| Expiry date | Mar 8, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N23/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This disclosure is directed to a method of inspecting how contact holes or via holes are formed in a sample, such as a wafer. An electron beam is directed to the contact holes in succession. An absorbed current flowing through the sample is detected by a current amplifier. Data about the obtained absorbed current is stored in a memory. The electric current flowing through a reference sample and ground is measured, and the relation of the current to the etch depths of contact holes into the substrate is previously found. A control unit compares data about the measured current with the previously found relation and determines the depths of holes of interest into the substrate (i.e., inspects how they are etched).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.