CD SEM automatic focus methodology and apparatus for...

Details CD SEM automatic focus methodology and apparatus for... CD SEM automatic focus methodology and apparatus for...

2005-12-27

2005-12-27

Wells, Nikita (Department: 2881)

Radiant energy

Inspection of solids or liquids by charged particles

Methods

C250S310000, C250S397000, C345S215000

Reexamination Certificate

active

06979820

ABSTRACT:
A method and apparatus for scanning electron microscope measurements which maintains a constant e-beam dose to the surface of a wafer being measured and thereby maintains a constant resist shrinkage. The apparatus provides a magnetic lens, a movable wafer holder to adjust the distance between a wafer and the magnetic lens, an image detector, means to determine the distance between the wafer and the magnetic lens, a retarding voltage applied to the wafer holder, means to adjust the retarding voltage, and means to focus the magnetic lens. The apparatus also provides feedback systems between the movable wafer holder and the means to determine the distance between the wafer and the magnetic lens, between the image detector and the means to adjust the retarding voltage, and between the image detector and means to focus the magnetic lens so these adjustments can be made automatically. The method first sets the distance between the wafer and the magnetic lens. The method next determines the charge on the wafer and adjusts the retarding voltage accordingly, thereby maintaining a constant accelerating voltage for the electron beam regardless of charge on the wafer. Finally the method focuses the magnetic objective lens. Maintaining a constant accelerating voltage for the electron beam regardless of charge on the wafer maintains constant resist shrinkage regardless the amount of charge on the wafer.

REFERENCES:
patent: 5025165 (1991-06-01), Chen et al.
patent: 5916716 (1999-06-01), Butsch et al.
patent: 6066849 (2000-05-01), Masnaghetti et al.
patent: 6084238 (2000-07-01), Todokoro et al.
patent: 6114681 (2000-09-01), Komatsu
patent: 6130432 (2000-10-01), Pfeiffer et al.
patent: 2003/0218133 (2003-11-01), Petrov et al.
patent: 2004/0211899 (2004-10-01), Ezumi et al.
“193nm Resist Shrinkage”, by Su et al., Solid State Technology, May 2001, pp. 52-54 and 57.
U.S. Appl. No. 10/047,266, Filed Jan. 14, 2002, “Reducing Photoresist Shrinkage via Plasma Treatment”, assigned to the Same Assignee.

Affiliated with

Also associated with

Rating

CD SEM automatic focus methodology and apparatus for... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with CD SEM automatic focus methodology and apparatus for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CD SEM automatic focus methodology and apparatus for... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3501942