Methods for manufacturing semiconductor devices

1. A method for manufacturing a semiconductor device, the method comprising:

depositing an insulating layer on a semiconductor substrate;

forming an opening of the insulating layer exposing a field region of the semiconductor substrate;

forming a trench in the semiconductor substrate on the exposed region in the opening;

performing independently an adsorption reaction of TEOS and a decomposition/recomposition reaction of TEOS using O 3 , thus depositing an oxide layer in a thin thickness on the surface of the semiconductor substrate; and

depositing repeatedly the oxide layer to bury a plurality of the oxide layer in the trench.

2. A method as defined by claim 1 , wherein depositing the oxide layer comprises:

introducing TEOS in a reactor having a high temperature of 500 to 600° C. and a low pressure of below 100 torr to adsorb TEOS on the semiconductor substrate;

interrupting the introduction of TEOS and discharging remaining TEOS from the reactor, and

providing the pressure of the reactor with a base pressure of above 100 torr and introducing O 3 in the reactor to decompose and recompose the adsorbed TEOS, thus depositing the oxide layer on the semiconductor substrate.

3. A method as defined by claim 2 , wherein before the adsorption of TEOS, the semiconductor substrate is cleaned and annealed in the reactor.

4. A method as defined by claim 3 , wherein the semiconductor substrate is cleaned in an HCl solution.

5. A method as defined by claim 4 , wherein the semiconductor substrate is annealed in the reactor in an atmosphere of O 3 .

6. A method as defined by claim 5 , wherein the semiconductor substrate is annealed in a temperature of 500 to 600° C.

7. A method as defined by claim 1 , wherein the oxide layer is deposited in a thickness of a few Å.