Method of forming trench in semiconductor substrate
AssigneeUnited Microelectronics Corp.
InventorsTong-Yu Chen, Chih-Jung Wang
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Abstract
The present invention provides a method of forming a trench in a semiconductor substrate. First, a first patterned mask layer is formed on a semiconductor substrate. The first patterned mask layer has a first trench. Then, a material layer is formed along the first trench. Then, a second patterned mask layer is formed on the material layer to completely fill the first trench. A part of the material layer is removed when the portion of the material layer between the second patterned mask layer and the semiconductor substrate is maintained so as to form a second trench. Lastly, an etching process is performed by using the first patterned mask layer and the second patterned mask layer as a mask.
Claims12
A method of forming a trench in a substrate, comprising:
- providing a substrate;
- forming a first patterned mask layer on the substrate, wherein the first patterned mask layer has a first trench;
- forming a material layer comprehensively on the substrate, wherein the material layer is formed on a bottom surface and at least a sidewall of the first trench;
- forming a second mask layer on the material layer to completely fill the first trench;
- completely removing the second mask layer outside the first trench to keep the second mask layer filled in the first trench to form a second patterned mask layer;
- removing a portion of the material layer and maintaining the portion of the material layer between the second patterned mask layer and the substrate to form at least a second trench between the first patterned mask layer and the second patterned mask layer;
- and
- after forming the second trench, performing an etching process by using the first patterned mask layer and the second patterned mask layer as a mask.
Dependencies are inferred from the claim text.