Mask material conversion
First Claim
1. A method for semiconductor processing, comprising:
- forming a plurality of spacers on a substrate by pitch multiplication, the spacers formed of a spacer material, wherein forming the plurality of spacers comprises;
providing a plurality of spaced-apart mandrels;
depositing a blanket layer of the spacer material on the mandrels;
anisotropically etching the spacer material to define the spacers; and
preferentially removing the mandrels;
expanding a volume of the spacer material forming the spacers by converting the spacer material to a material occupying a larger volume than the spacer material;
forming a photodefinable layer extending over the spacers; and
patterning the photodefinable layer.
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Accused Products
Abstract
The dimensions of mask patterns, such as pitch-multiplied spacers, are controlled by controlled growth of features in the patterns after they are formed. To form a pattern of pitch-multiplied spacers, a pattern of mandrels is first formed overlying a semiconductor substrate. Spacers are then formed on sidewalls of the mandrels by depositing a blanket layer of material over the mandrels and preferentially removing spacer material from horizontal surfaces. The mandrels are then selectively removed, leaving behind a pattern of freestanding spacers. The spacers comprise a material, such as polysilicon and amorphous silicon, known to increase in size upon being oxidized. The spacers are oxidized to grow them to a desired width. After reaching the desired width, the spacers can be used as a mask to pattern underlying layers and the substrate. Advantageously, because the spacers are grown by oxidation, thinner blanket layers can be deposited over the mandrels, thereby allowing the deposition of more conformal blanket layers and widening the process window for spacer formation.
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Citations
13 Claims
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1. A method for semiconductor processing, comprising:
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forming a plurality of spacers on a substrate by pitch multiplication, the spacers formed of a spacer material, wherein forming the plurality of spacers comprises; providing a plurality of spaced-apart mandrels; depositing a blanket layer of the spacer material on the mandrels; anisotropically etching the spacer material to define the spacers; and preferentially removing the mandrels; expanding a volume of the spacer material forming the spacers by converting the spacer material to a material occupying a larger volume than the spacer material; forming a photodefinable layer extending over the spacers; and patterning the photodefinable layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification