Patent · US Expired

Ultrasonic photoresist process monitor and method

US6250161A · kind A · utility

3Cited by
12References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 16, 1998
Grant dateJun 26, 2001
Priority date
Expiry dateJul 16, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2291/048
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

There is provided a monitor and method for monitoring the condition of a photoresist film on a wafer in which the phase of high frequency ultrasonic pulses reflected from the wafer/photoresist interface provides an indication of the condition of the photoresist film.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.