Method of manufacturing dummy gates in gate last process
First Claim
1. A method of manufacturing a dummy gate in a gate last process, which comprises the following steps:
- forming a dummy gate material layer and a hard mask material layer sequentially on a substrate;
etching the hard mask material layer to form a top-wide-bottom-narrow hard mask pattern; and
dry etching the dummy gate material layer using the hard mask pattern as a mask to form a top-wide-bottom-narrow dummy gate,wherein the hard mask material layer comprises a first mask layer and a second mask layer located on the first mask layer, andwherein the top-wide-bottom-narrow hard mask pattern is formed by wet etching the hard mask material layer in a single step with wet etching solution, which etches the first mask layer faster than etches the second mask layer.
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Abstract
The present invention provides a method of manufacturing a dummy gate in a gate last process, which comprises the steps of forming a dummy gate material layer and a hard mask material layer sequentially on a substrate; etching the hard mask material layer to form a top-wide-bottom-narrow hard mask pattern; dry etching the dummy gate material layer using the hard mask pattern as a mask to form a top-wide-bottom-narrow dummy gate. According to the dummy gate manufacturing method of the present invention, instead of vertical dummy gates used conventionally, top-wide-bottom-narrow trapezoidal dummy gates are formed, and after removing the dummy gates, trapezoidal trenches can be formed. It facilitates the subsequent filling of the high-k or metal gate material and enlarges the window for the filling process; as a result, the device reliability will be improved.
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Citations
9 Claims
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1. A method of manufacturing a dummy gate in a gate last process, which comprises the following steps:
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forming a dummy gate material layer and a hard mask material layer sequentially on a substrate; etching the hard mask material layer to form a top-wide-bottom-narrow hard mask pattern; and dry etching the dummy gate material layer using the hard mask pattern as a mask to form a top-wide-bottom-narrow dummy gate, wherein the hard mask material layer comprises a first mask layer and a second mask layer located on the first mask layer, and wherein the top-wide-bottom-narrow hard mask pattern is formed by wet etching the hard mask material layer in a single step with wet etching solution, which etches the first mask layer faster than etches the second mask layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification