Abstract: A method for improving gate oxide thinning issue at trench corners is disclosed. The method comprises steps as follows. Firstly, a silicon substrate having a trench therein is provided. HDPCVD technology to form a first oxide layer on the sidewall and the bottom of the trench is carried out. After performing an etchback to leave the first oxide layer on the bottom of the trench, a second oxide layer is formed on the first oxide layer and on sidewalls of the trench by LPCVD technology. Thereafter, an isotropic etching is performed so as to remove a substantially portion of the second oxide layer and leave a remnant portion of second oxide layer on the trench corners. As a consequently, the trench corners are smooth. Finally, a thermal oxidation to form a third oxide layer on the sidewall of the trench is carried achieved to accomplish the gate oxide formation.

Abstract: The present invention discloses a method to detect organic contamination in process environment of integrated circuits by using hemispherical-grain polysilicon layer that is formed in the process environment. The organic residue will contaminates the substrate which the hemispherical-grain polysilicon layer is formed thereon so as that the grain size of the polysilicon layer is between about 0.2 to 0.4 micrometers. The grain size of the hemispherical-grain polysilicon layer that is fabricated in a clean process environment is between about 0.5 to 0.8 micrometers. In other words, if organic contamination is residual in process environment, the grain size of the hemispherical-grain polysilicon layer that is fabricated in the process environment is smaller than a certain size to determine that the process environment is contaminated by organic contamination.

Abstract: A method of removing a polysilicon buffer in a method of forming a field oxide and an active area is disclosed herein that comprises the step of applying an etching selectivity solution to the polysilicon buffer to substantially remove the polysilicon buffer without substantially affecting the field oxide, a pad oxide, and the substrate. An etching selectivity solution is defined herein is a solution that has an etching rate for one material that is higher than for another material. In this case, the etching selectivity solution has an etching rate for polysilicon material that is higher than its etching rate for field oxide material. Accordingly, when the etching selectivity solution is applied to the polysilicon buffer, it will substantially etch off the polysilicon buffer without substantially affecting the field oxide. In the preferred embodiment, the etching selectivity solution comprises a mixture of HF and HNO3, or HF, HNO3 and CH3COOH.

Abstract: A hanger for supporting a pair of eyeglasses. The hanger has a central portion, two arms which extend away from the central portion and which terminate at end portions. Each end portion has a respective opening into which is inserted a respective temple bar of the pair of eyeglasses. The central portion has an aperture into which is inserted a support arm for balancing the eyeglasses. The aperture is substantially equidistant from the openings in the end portions. The arms have a lower edge which defines a space directly between the end portions.