Samsung Electronics Co., Ltd.

Chan Sik Park

Han Seong Kim

Kyung Hawn Cho

Se Hyoung Ryu

Yun Young Kwon

Jang Hyeok Lee

Eung Yong Ahn

Won Soon Lee

A method of forming a hemispherical grain includes cleaning a polysilicon layer of a native oxide in-situ in the processing chamber of the HSG growth reactor. Such a native oxide adversely affects the growing of HSGs from seeds during the thermal treatment performed in the processing chamber. The cleaning is carried out by dry etching the polysilicon layer with plasma. The plasma may be produced from a mixture of fluorine and inert gases having a volumetric ratio within the range of 0.2:100 to 25:100. Such a plasma can be formed by ionizing the gas with an RF power within a range of 20 to 500 Watts. An advantage of using plasma etching to clean the polysilicon of a native oxide is that the plasma etching is an anisotropic process. The present invention is thus particularly useful in the manufacture of a DRAM capacitor. In such a case, the hemispherical grains at neighboring side walls of the DRAM capacitor have a smaller average grain size than that of the hemispherical grains at the upper surfaces of the capacitor. The smaller HSGs are less likely to bridge, and yet the capacitor may still have some comparatively large grains contributing to the increased capacitance provided by the HSGs.

Method of forming hemispherical grains on a surface comprising pre-cleaning the surface in-situ with plasma

A method for forming trench isolation in the silicon substrate is disclosed. This method allows for an improved bonding force between the sidewall silicon dioxide layer and the sidewall of the trench. After a trench is formed, sidewall silicon dioxide is grown on the sidewall of the trench by a first oxidation process. Then, PE-TEOS is deposited on the silicon substrate and the sidewall of the trench. The PE-TEOS layer around the entrance of the trench is then etched back using argon gas. The second oxidation process or the first annealing proceeds to enhance the bonding force between the sidewall silicon dioxide layer and the sidewall of the trench. After the second oxidation process or the annealing, the trench is filled with O.sub.3 -TEOS, and then PE-TEOS is deposited over the O.sub.3 -TEOS layer. Finally, the second annealing process follows.

Method for forming a trench isolation structure comprising an interface

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Suwon, South Korea

Chan Sik Park