Semiconductor device manufacturing: process – With measuring or testing
Reexamination Certificate
2001-04-06
2003-09-02
Nelms, David (Department: 2818)
Semiconductor device manufacturing: process
With measuring or testing
Reexamination Certificate
active
06613589
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to the improvement of substrate alignment, for example in the manufacture of semiconductors.
The manufacture of semiconductors requires that patterned layers be aligned to specific underlying features. The amount of misalignment is readily measurable, using commercially available instruments and procedures. It is desirable to minimize misalignment. Exposure tools, such as a stepper, typically allow measured corrections to be entered so that alignment is improved on subsequent wafers.
Stepper alignment connections are typically made by measuring the alignment and reversing the measured component offsets.
There exists a problem in that one correction can interact with another, and also the response to a correction may be some fraction of the actual programmed value.
SUMMARY OF THE INVENTION
The present invention is concerned with improving the pattern alignment, i.e., reduce the pattern misalignment by calibrating the stepper and measuring component responses. These responses are regressed and input into a response matrix. The response matrix is then used to predict the required component offsets by solving the relevant set of linear equations.
Broadly, the invention is to a method for improving alignment of a substrate on a stepper, comprising the steps of imposing predetermined corrections for each of a plurality of substrates, a set of corrections for each substrate, measuring the actual corrections which occur on each substrate, mathematically processing the actual corrections to produce a matrix and provide a plurality of equations, and resolving the equations to provide a set of input corrections to provide a correct alignment.
REFERENCES:
patent: 5668042 (1997-09-01), Bae
patent: 5877861 (1999-03-01), Ausschnitt et al.
patent: 6338971 (2002-01-01), Yasuda et al.
Hoang Quoc D
Nelms David
Zawilski Peter
LandOfFree
Method for improving substrate alignment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for improving substrate alignment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for improving substrate alignment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3004099