Layer forming method and apparatus
There is provided a method and apparatus for forming a layer, by sequentially repeating a layer deposition cycle to process a substrate disposed in a reaction chamber. The deposition cycle comprising: supplying a first precursor into the reaction chamber for a first pulse period; supplying a second precursor into the reaction chamber for a second pulse period. At least one of the first and second precursors may be supplied into the reaction chamber for a pretreatment period longer than the first or second pulse period before sequentially repeating the deposition cycles.
1. A method of forming a layer comprising silicon nitride, comprising:
providing a substrate in a reaction chamber;
performing a pretreatment step for a pretreatment period;
after the pretreatment step, sequentially repeating a deposition cycle to deposit at least a portion of the layer on the substrate disposed in the reaction chamber, the deposition cycle comprising:
supplying a first precursor into the reaction chamber for a first pulse period;
removing a portion of the first precursor from the reaction chamber;
supplying a second precursor into the reaction chamber for a second pulse period; and
removing a portion of the second precursor from the reaction chamber;
wherein the first precursor comprises a silicon halide;
wherein the second precursor comprises a nitriding gas;
wherein the silicon halide is supplied into the reaction chamber for the pretreatment period such that the silicon halide is supplied to the reaction chamber during both the pretreatment step and the deposition cycle, the pretreatment period being longer than the first or second pulse period;
wherein the first precursor is supplied to the reaction chamber between 1.5 and 4 times longer than the second precursor during sequentially repeating a deposition cycle, and wherein the amount of the second precursor supplied to the reaction chamber is between 2 and 15 times more than the first precursor supplied to the reaction chamber during sequentially repeating a deposition cycle; and
wherein both the first precursor and the second precursor are supplied into the reaction chamber simultaneously during the pretreatment period to deposit a nucleation layer.
2. The method according to claim 1 , wherein the pretreatment period is between 2 to 1200 times longer than the first or second pulse period.
3. The method according to claim 1 , wherein the pretreatment period is between 1 to 60 minutes.
4. The method according to claim 1 , wherein sequentially repeating the deposition cycle takes between 1 to 180 minutes.
5. The method according to claim 1 , wherein the first pulse period is between 1 to 180 seconds.
6. The method according to claim 1 , wherein the second pulse period is between 1 to 180 seconds.
7. The method according to claim 1 , wherein the pressure in the reaction chamber during the pretreatment step is higher than the pressure in the reaction chamber during the deposition cycle.
8. The method according to claim 1 , wherein the pressure in the reaction chamber during the pretreatment step is at least twice the pressure in the reaction chamber during the deposition cycle.
9. The method according to claim 1 , wherein the first precursor is selected from the group consisting of chlorosilane, dichlorosilane, trichlorosilane, tetrachlorosilane, iodosilane, diiodosilane, tribromosilane, silicic acid, tetraiodosilane, tetrabromosilane, tetrafluorosilane, chlorotrifluorosilane, dichlorodifluorosilane, and trichlorofluorosilanedichlorsilane.
10. The method according to claim 1 , wherein the second precursor comprises hydrazine (N 2 H 4 ).
11. The method according to claim 1 , wherein the first or second precursor is not activated by a plasma.
12. The method according to claim 1 , wherein the first precursor comprises at least one of fluorine, chlorine, bromine, or iodine.
13. The method according to claim 1 , wherein the nucleation layer is one monolayer thick.
14. The method according to claim 1 , wherein the first precursor is supplied to the reaction chamber between 2 and 3 times longer than the second precursor during sequentially repeating a deposition cycle.
15. The method according to claim 1 , wherein the deposition cycles are repeated between 2 to 100 times.
16. The method according to claim 1 , wherein the layer comprises silicon nitride and the silicon concentration in the deposited layer is between 1 to 33% higher than stoichiometric concentration of silicon in Si 3 N 4 —.
17. The method according to claim 1 , wherein the method comprises providing a dopant selected from the group consisting of AsH 3 and SbH 3 —.
18. The method according to claim 1 , wherein the method is used in a vertical furnace.