Focus or exposure dose parameter control system using tone reversing patterns
AssigneeInternational Business Machines Corporation
InventorsChristopher P. Ausschnitt, Timothy A. Brunner, Mark E. Lagus
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Abstract
Focus and exposure parameters may be controlled in a lithographic process for manufacturing microelectronics by creating a complementary tone pattern of shapes and spaces in a resist film on a substrate. Corresponding dimensions of the resist shape and space are measured and the adequacy of focus or exposure dose are determined as a function of the measured dimensions. Etching parameters may also be controlled by creating a complementary tone pattern of etched shapes and spaces on a substrate. Corresponding dimensions of the etched shape and space are measured and the adequacy of etching parameters are determined as a function of the measured dimensions.
Claims10
A process for controlling focus or exposure dose parameters in a lithographic process comprising the steps of:
- a) exposing a plurality of a first set of complementary tone patterns onto a resist film layer having a resist threshold disposed on a substrate, each of said first set of complementary tone patterns comprising:
- i) a first pattern portion having a shape which corresponds to an area on the resist film having an exposure dose below the resist threshold of the resist film and ii) a second pattern portion having a space which corresponds to an area on the resist film having an exposure dose above the resist threshold of the resist film, said shape and space having corresponding dimensions, each of said exposed first set of complementary tone patterns being exposed on said resist film under different focus or exposure dose conditions;
- b) measuring said dimensions of image shapes and spaces on each of said exposed first set of complementary tone patterns;
- c) determining optimum focus or exposure dose conditions based on the measurements of step (b);
- d) determining the dependence of focus or exposure dose conditions on said dimensions of the image shapes and spaces near the optimum focus or exposure dose conditions determined in step (c);
- e) exposing one or more of a second set of complementary tone patterns onto a resist film layer having a resist threshold disposed on a substrate, each of said second set of complementary tone patterns comprising:
- i) a first pattern portion having a shape which corresponds to an area on the resist film having an exposure dose below the resist threshold of the resist film and ii) a second pattern portion having a space which corresponds to an area on the resist film having an exposure dose above the resist threshold of the resist film, said shape and space having corresponding dimensions;
- f) measuring said dimensions of image shapes and spaces on each of said exposed second set of complementary tone patterns;
- and
- g) determining adequacy of focus or exposure dose parameters on each of said exposed second set of complementary tone patterns based on the measurements and determinations of steps (a)-(d).
Dependencies are inferred from the claim text.