US 8,274,645 B2 · Method and apparatus for in-situ metrology of a workpiece disposed in a vacuum processing chamber

Abstract

A method and apparatus for in-situ metrology of a workpiece disposed in a vacuum processing chamber. The apparatus may include an optical assembly external to the processing chamber configured to focus a relatively large optical spot over a relatively large working distance to acquire a TE and TM spectra from a periodic array on the workpiece. The workpiece may be disposed in the processing chamber with an arbitrary orientation which is first determined via a reflectance measurement. TE and/or TM spectra may then be acquired by initiating a periodic triggering of a flash lamp based on the determined workpiece orientation to account for variation in placement of the workpiece within the processing chamber. The periodic array from which spectra are collected may be a memory array being fabricated in a semiconductor wafer.

Claims19

Dependent claims

A vacuum processing apparatus for obtaining in-situ scatterometry data comprising:

a process chamber configured to perform a plasma process on a workpiece disposed at an arbitrary fixed orientation;
an optics assembly to focus an optical spot having an area smaller than the workpiece onto a periodic array disposed on the workpiece while the workpiece is disposed in the process chamber;
a linear polarizer in an optical path of the optics assembly and to rotate a polarization axis through a plurality of angular positions relative to the fixed workpiece orientation;
a flash lamp coupled to the optical path to periodically illuminate the periodic array within the optical spot;
a trigger line to trigger the flash lamp when the polarizer is rotated to a predetermined angular position relative to the fixed workpiece orientation;
and
a spectrometer to output reflectance spectra collected from the periodic array when periodically illuminated by the flash lamp.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for in-situ metrology of a workpiece disposed in a vacuum processing chamber

Life of this patent

Method and apparatus for in-situ metrology of a workpiece disposed in a vacuum processing chamber

Life of this patent

Abstract

Claims19