Resist hardening process having improved thermal stability
First Claim
1. A method for patterning a layer disposed on a semiconductor substrate, said method comprising:
- disposing a photoresist on the layer;
forming a pattern in the photoresist, the pattern including at least a first feature having a first width and a second feature having a second width which is greater than the first width;
irradiating the second feature with radiation and not irradiating the first feature with the radiation; and
etching the layer having the photoresist thereon to pattern the layer.
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Accused Products
Abstract
The present invention is directed to a method of hardening a photoresist formed on a patterned layer during photolithograpy, without causing undesirable shrinkage of the resist features. The patterned layer is disposed on a semiconductor substrate, and the photoresist layer is disposed on the patterned layer in a conventional manner. The photoresist layer is irradiated and developed in a conventional manner to have the desired pattern formed therein. The larger features of the developed photoresist layer are irradiated without heat to thereby harden these features, without irradiating the smaller features. The hardening may be performed by screening the smaller features from the radiation applied to the photoresist layer, or by scanning a beam across only the larger features. The radiation may be UV light or an electron beam. Alternatively, all of the features of the photoresist may be hardened by exposure to a basic atmosphere immediately before, during or immediately after irradiation with UV light. In both cases, the features are hardened without shrinkage. After the features are hardened, the photoresist and patterned layer are etched in a conventional manner to transfer the pattern to the patterned layer.
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Citations
30 Claims
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1. A method for patterning a layer disposed on a semiconductor substrate, said method comprising:
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disposing a photoresist on the layer; forming a pattern in the photoresist, the pattern including at least a first feature having a first width and a second feature having a second width which is greater than the first width; irradiating the second feature with radiation and not irradiating the first feature with the radiation; and etching the layer having the photoresist thereon to pattern the layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 27, 28, 29, 30)
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21. A method for hardening a photoresist developed upon a layer formed upon a semiconductor substrate, the photoresist developed to have a plurality of first features spaced from each other and having substantially the same width and at least one second feature spaced from said first features and having a width which is greater than the width of the first features, said method including:
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disposing a mask over said first features and projecting radiation upon the photoresist, wherein, the radiation irradiates and thereby hardens the second feature, and the mask is opaque to the radiation such that the radiation does not irradiate the first features. - View Dependent Claims (22, 23, 24, 25)
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26. A method for hardening a photoresist developed upon a layer formed upon a semiconductor substrate, the photoresist developed to have a plurality of first spaced features having substantially the same width and at least one second feature spaced from said first features and having a width which is greater than the width of the first features, said method including:
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directing radiation at a location at one side of the second feature and scanning the radiation over the second feature without scanning the first features, wherein, the radiation irradiates and thereby hardens the second feature, and does not irradiate the first features.
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Specification