Samsung Electronics Co., Ltd.

Kyung Hawn Cho

Sang Kook Choi

Won Sik An

Chung Hwan Kwon

Han Seong Kim

Chan Sik Park

Won Soon Lee

A method for forming a dual oxide layer on a silicon substrate provides that layer having varying thicknesses by using a damage layer formed on the silicon substrate, or a silicon nitride layer deposited on the silicon substrate. The damage layer is formed on the silicon substrate by dry etching a designated part of the silicon substrate, and the dual oxide layer is formed by using the properties of SiO by which the oxide layer growth speed on the damage layer is slower than that on the silicon substrate. A pattern of the damage layer is defined by photolithography, and the damage layer having a depth of about 20 to 5,000 &angst; is formed using CF , CHF , or Ar gas at a pressure of 900 mTorr or less, or using Cl or HBr. In the preoxidation cleaning step, a solution containing NH F, HF, and H O, a standard solution containing NH OH, H O , and H O, and/or HF are used. Meanwhile, using the nitride layer, after depositing the silicon nitride to a thickness of about 10 to about 100 &angst; on the silicon substrate, a pattern of the silicon nitride layer is defined by photolithography and the silicon nitride layer is partially removed depending on the pattern.

Method for simultaneously forming thinner and thicker parts of a dual oxide layer having varying thicknesses

A method for forming a dual oxide layer on a silicon substrate provides that layer having varying thicknesses by using a damage layer formed on the silicon substrate, or a silicon nitride layer deposited on the silicon substrate. The damage layer is formed on the silicon substrate by dry etching a designated part of the silicon substrate, and the dual oxide layer is formed by using the properties of SiO,by which the oxide layer growth speed on the damage layer is slower than that on the silicon substrate. A pattern of the damage layer is defined by photolithography, and the damage layer having a depth of about 20 to 5,000 &angst; is formed using CF,, CHF,, or Ar gas at a pressure of 900 m Torr or less, or using Cl,or HBr. In the preoxidation cleaning step, a solution containing NH,F, HF, and H,O, a standard solution containing NH,OH, H,O,, and H,O, and/or HF are used. Meanwhile, using the nitride layer, after depositing the silicon nitride to a thickness of about 10 to about 100 &angst; on the silicon substrate, a pattern of the silicon nitride layer is defined by photolithography and the silicon nitride layer is partially removed depending on the pattern.

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.

Growing community of inventors

Kyungki-do, South Korea

Kyung Hawn Cho