Etching apparatus
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsWan-Yu Lee, Ying-Hao Kuo, Hai-Ching Chen, Tien-I Bao
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Abstract
A system and method of etching a semiconductor device are provided. Etching solution is sampled and analyzed by a monitoring unit to determine a concentration of components within the etching solution, such as an oxidant concentration. Then, based upon such measurement, a makeup amount of the components may be added be a makeup unit to the etching solution to control the concentration of the components within the etching system.
Claims20
A method of etching a semiconductor device, the method comprising:
- filling an etchant tank with a liquid etching solution;
- after filling the etchant tank, submerging a surface of a substrate in the liquid etching solution;
- removing a sample from the liquid etching solution;
- analyzing the sample to determine a concentration of an oxidant within the sample;
- introducing a makeup amount of the oxidant into the liquid etching solution based upon the concentration of the oxidant from analyzing the sample;
- and
- etching a semiconductor substrate with the liquid etching solution to form an etched surface, wherein after the etching the semiconductor substrate the etched surface is free from hillocks.
A method of manufacturing a semiconductor device, the method comprising:
- receiving a substrate into an etchant tank holding an etchant, the etchant comprising a strong base, a surfactant, and an oxidant;
- removing a sample of the etchant from the etchant tank and sending the sample to a monitoring unit, the monitoring unit comprising an oxidant analysis unit;
- analyzing the sample of the etchant;
- determining an amount of makeup to add to the etchant in the etchant tank;
- mixing in a makeup unit one or more of a makeup strong base, a makeup surfactant, and a makeup oxidant to form the amount of makeup, the makeup unit coupled to a first output from a strong base unit, a second output from a surfactant unit, and a third output from an oxidant unit;
- and
- adding the amount of makeup to the etchant.
A method of manufacturing a semiconductor device, the method comprising:
- applying an etchant to a surface of a substrate, the surface being submerged in the etchant, the substrate and the etchant being located in an etching tank, the etchant comprising:
- a strong base to etch the substrate;
- a surfactant to modify a selectivity of the etchant to a first crystallographic orientation;
- and
- an oxidant to react with the substrate to repel chemical reaction by-products from a surface of the substrate and impede hillock regrowth;
- analyzing a first concentration of the strong base;
- analyzing a second concentration of the surfactant separately from the analyzing the first concentration of the strong base;
- analyzing a third concentration of the oxidant separately from the analyzing the first concentration of the strong base and separately from the analyzing the second concentration of the surfactant;
- determining an amount to add of each of the strong base, the surfactant, and the oxidant;
- mixing a first makeup amount of the strong base, a second makeup amount of the surfactant, and a third makeup amount of the oxidant to form a makeup stream;
- and
- titrating the makeup stream into the etchant.
Dependencies are inferred from the claim text.