Method for manufacturing semiconductor device
View Patent ↗Provided is a method for manufacturing a semiconductor device capable of preventing a solution from penetrating a lower layer by forming a poly silicon layer stacked of the films having the different grain boundary structures at border, wherein the solution is used in the subsequent strip and cleaning process.
1. A method for manufacturing a semiconductor device comprising:
providing a semiconductor substrate on which elements are formed;
forming a first layer on the semiconductor substrate;
performing a nitrogen purge process to change the grain boundary structure of an upper surface of the first layer such that the first layer has a first grain boundary structure; and
forming a second layer having a second grain boundary structure on the first layer,
wherein the first layer and the second layer are formed by sequentially performing a pre-deposition step, a deposition step and a pumping step, and the first layer and the second layer have different grain boundary structures.
2. The method of claim 1 , wherein the first layer and the second layer comprise polysilicon.
3. The method of claim 1 , wherein the nitrogen purge process is performed in situ during the forming of the lower film layer.
4. The method of claim 1 , wherein the nitrogen purge process is performed with nitrogen gas at a pressure in the range of 0.1 Torr to 0.5 Torr and a temperature in the range of 580° C. to 650° C.
5. The method of claim 1 , wherein the film having at least a lower film layer and an upper film layer is formed through a deposition process, and said deposition process is performed with silane gas at a pressure in the range of 0.1 Torr to 0.5 Torr and a temperature in the range of 580° C. to 650° C.
6. A method for manufacturing a semiconductor device comprising:
providing a semiconductor substrate on which elements are formed;
forming a first polysilicon film on the semiconductor substrate by sequentially performing a first pre-deposition step, a first deposition step and a first pumping step;
performing a first nitrogen purge process to change the grain boundary structure of an upper surface of the first polysilicon film such that the first layer has a first grain boundary structure;
forming a second polysilicon film on the first polysilicon film by sequentially performing a second pre-deposition step, a second deposition step and a second pumping step;
performing a second nitrogen purge process to change the grain boundary structure of an upper surface of the second polysilicon film such that the second polysilicon film has a second grain boundary structure; and
forming a third polysilicon film having a third grain boundary structure on the second polysilicon film by sequentially performing a third pre-deposition step, a third deposition step and a third pumping step,
wherein the first, second and third polysilicon films have different grain boundary structures.
7. The method of claim 6 , wherein the first and the second nitrogen purge process are performed with nitrogen gas at a pressure in the range of 0.1 Torr to 0.5 Torr and a temperature in the range of 580° C. to 650° C.
8. The method of claim 6 , wherein the first, the second and the third polysilicon film are formed through a deposition process, and said deposition process is performed with silane gas at a pressure in the range of 0.1 Torr to 0.5 Torr and a temperature in the range of 580° C. to 650° C.