Method of forming chalcogenide thin film

1. A method of forming a chalcogenide thin film, the method comprising:

loading a substrate in which a pattern is formed, into a reactor;

supplying a source gas to the substrate;

supplying a first purge gas to the substrate so as to purge the source gas supplied to the substrate;

supplying a reaction gas that is used to reduce the source gas, to the substrate;

supplying a second purge gas to the substrate so as to purge the reaction gas supplied to the substrate; and

repeatedly performing a cycle comprising the supplying of the source gas through the supplying of the second purge gas,

wherein the source gas is formed of one or more selected from the group including germanium (Ge)-based gas, gallium (Ga)-based gas, indium (In)-based gas, selenium (Se)-based gas, antimony (Sb)-based gas, tellurium (Te)-based gas, tartar (Sn)-based gas, silver (Ag)-based gas, and sulfur (S)-based gas, and

wherein at least one of a time changing operation by which a supply time of the first purge gas is changed whenever the cycle is repeated and a pressure adjustment operation by which the pressure in the reactor is adjusted during the supply of the first purge gas is performed so that a deposition rate of an inside of the pattern is greater than that of an upper portion of the pattern; and

between the loading of the substrate and the supplying of the source gas, processing a surface of the substrate by generating plasma in the substrate by using a gas containing fluorine (F).

2. The method of claim 1 , wherein at least one of the time varying operation and the pressure adjustment operation is performed so that the deposition rate of the inside of the pattern is greater than 0.5 Å per the cycle.

3. The method of claim 1 , wherein the supplying of the reaction gas comprises applying a bias voltage to at least one of the reactor and an inside of the reactor

4. The method of claim 1 , wherein the time at which the first purge gas is supplied is set in a range from 0.1 to 5 seconds, or pressure inside the reactor is set in a range from 0.5 to 10 torr.

5. The method of claim 1 , wherein the chalcogenide thin film is formed of one or more material selected from the group including a Ge—Sb—Te compound, GaSb, InSb, InSe, Sb 2 Te 3 GeTe, Ge 2 Sb 2 Te 5 , InSbTe, GaSeTe, Sn s b 2 Te 4 , InSbGe, AgInSbTe, (GeSn)SbTe, GeSb(SeTe), and Te 81 Ge 15 Sb 2 S 2 .

6. The method of claim 1 , wherein the Ge-based gas is one or more selected from the group including compounds represented by Formulae 1 through 4 below:

wherein R 1 through R 5 are each C n H 2n+1 or N(C n H 2n+1 *C m H 2m+1 ), R 6 through R 11 are each any one of H, C n H 2n+1 , and N(C n H 2n+1 .C m H 2m+1 ), and n and m are natural numbers.

7. The method of claim 1 , wherein the Sb-based gas is a compound represented by Formula 5 below

wherein, R 12 through R 14 are each any one of H, C n H 2n+1 and N(C n H 2n+1 .C m H 2m+1 ) and n and m are natural numbers.

8. The method of claim 1 , wherein the Te-based gas is a compound, represented by Formula 6 below

R 15 —Te—R 16   (6)

wherein R 15 and R 16 are each H, C n H 2n+1 and N(C n H 2n+1 C m H 2m+1 ) and n and m are natural numbers.

9. The method of claim 1 , wherein the reaction gas is a compound containing hydrogen (H).

10. The method of claim 1 , wherein the first purge gas and the second purge gas are one or more selected from nitrogen (N 2 ), argon (Ar), and helium (He).

11. The method of claim 1 , wherein the gas containing F is NF 3 .

12. The method of claim 1 , wherein a temperature of the substrate about when the supplying of the source gas through the repeatedly performing of the cycle is 100° C. to 400° C.