Method for forming Si-containing film using two precursors by ALD
A method for forming a silicon-containing dielectric film on a substrate by atomic layer deposition (ALD) includes: providing two precursors, one precursor containing a halogen in its molecule, another precursor containing a silicon but no halogen in its molecule, adsorbing a first precursor, which is one of the two precursors onto a substrate to deposit a monolayer of the first precursor; adsorbing a second precursor, which is the other of the two precursors onto the monolayer of the first precursor to deposit a monolayer of the second precursor; and exposing the monolayer of the second precursor to radicals of a reactant to cause surface reaction with the radicals to form a compound monolayer of a silicon-containing film.
1. A method for forming a silicon-containing dielectric film on a substrate by atomic layer deposition (ALD), comprising:
(i) providing two precursors for forming a silicon-containing film, one precursor containing a halogen in its molecule, another precursor containing a silicon but no halogen in its molecule, said two precursors being reactive with each other in a gas phase;
(ii) adsorbing a first precursor in a gas phase, which is one of the two precursors without the other of the two precursors, onto a substrate to deposit a monolayer of the first precursor;
(iii) then adsorbing a second precursor in a gas phase, which is the other of the two precursors without the one of the two precursors, onto the monolayer of the first precursor to deposit a monolayer of the second precursor, wherein no radicals of a gas are supplied over the substrate between steps (ii) and (iii);
(iv) exposing the monolayer of the second precursor to radicals of a treating gas to cause surface reaction with the radicals to form a compound monolayer of a silicon-containing film; and
(v) repeating steps (ii) to (iv), which constitute one cycle of ALD, to form a silicon-containing dielectric film composed of multiple monolayers.
2. The method according to claim 1 , wherein the one precursor is a precursor containing a silicon in its molecule.
3. The method according to claim 2 , wherein the one precursor is a precursor containing a hydrocarbon in its molecule.
4. The method according to claim 1 , wherein the one precursor is a silicon halide.
5. The method according to claim 4 , wherein the one precursor is the first precursor.
6. The method according to claim 5 , wherein the one precursor is a silicon halide.
7. The method according to claim 1 , wherein the other precursor is a silicon alkylamide or aminosilane.
8. The method according to claim 1 , wherein the treating gas is at least one gas selected from the group consisting of rare gas, hydrogen, nitrogen, ammonia, hydrocarbon, and halogenated carbon.
9. The method according to claim 8 , wherein the treating gas is at least one gas selected from the group consisting of N 2 , He, Ne, Ar, H 2 , NH 3 , CH 4 , C x F y , C x Cl y , C x Br y , and C x I y , wherein x and y are integers.
10. The method according to claim 1 , wherein the radicals are radicals excited by plasma or thermally excited.
11. The method according to claim 10 , wherein the radicals are constituted by hydrogen and nitrogen plasmas.
12. The method according to claim 10 , wherein the radicals are radicals excited by plasma generated by RF power having a frequency of 400 kHz to 60 MHz.
13. The method according to claim 1 , further comprising removing a non-adsorbed portion of the first precursor from the surface of the substrate after step (ii) before step (iii), removing a non-adsorbed portion of the second precursor from the surface of the substrate after step (iii) before step (iv), and removing a non-reacted portion of the reactant from the surface of the substrate after step (iv) before subsequent step (ii).
14. The method according to claim 1 , wherein the temperature of the substrate is kept at 0 to 650° C. throughout the cycles.
15. The method according to claim 1 , wherein the other precursor further contains a hydrocarbon in its molecule, and in step (iii), the second precursor is adsorbed onto the monolayer of the first precursor by an exchange reaction between the halogen of the one precursor and the hydrocarbon of the other precursor.
16. A method for forming a silicon-containing dielectric film on a substrate by atomic layer deposition (ALD), comprising:
(i) providing two precursor for forming a silicon-containing film, one precursor containing a halogen in its molecule, another precursor containing a silicon but no halogen in its molecule, said two precursors being reactive with each other;
(ii) adsorbing a first precursor, which is one of the two precursors without the other of the two precursors, onto a substrate to deposit a monolayer of the first precursor;
(iii) then absorbing a second precursor, which is the other of the two precursors without the one of the two precursors, onto the monolayer of the first precursor to deposit a monolayer of the second precursor, wherein no radicals of a gas are supplied over the substrate between steps (ii) and (iii);
(iv) exposing the monolayer of the second precursor to radicals of a treating gas to cause surface reaction with the radicals to form a compound monolayer of a silicon-containing film; and
(v) repeating steps (ii) to (iv), which constitute one cycle of ALD, to form a silicon-containing dielectric film composed of multiple monolayers,
wherein the one precursor is at least one precursor selected from the group consisting of dichloromethylsilane, tetrachlorodimethyldisilane, dichlorotetramethyldisilane, bisdichloromethylsilylethane, chloromethyldichloromethylsilane, bisdimethylchlorosilylethane, bisdichloromethylsilylethane, chloromethyltrimethylsilane, and bischloromethyldimethylsilane.
17. A method for forming a silicon-containing dielectric film on a substrate by atomic layer deposition (ALD), comprising:
(i) providing two precursors for forming a silicon-containing film, one precursor containing a halogen in its molecule, another precursor containing a silicon but no halogen in its molecule, said two precursors being reactive with each other;
(ii) adsorbing a first precursor, which is one of the two precursors without the other of the two precursors, onto a substrate to deposit a monolayer of the first precursor;
(iii) then absorbing a second precursor, which is the other of the two precursors without the one of the two precursors, onto the monolayer of the first precursor to deposit a monolayer of the second precursor, wherein no radicals of a gas are supplied over the substrate between steps (ii) and (iii);
(iv) exposing the monolayer of the second precursor to radicals of a treating gas to cause surface reaction with the radicals to from a compound monolayer of a silicon-containing film; and
(v) repeating steps (ii) to (iv), which constitute one cycle of ALD, to form a silicon-containing dielectric film composed of multiple monolayers,
wherein the other precursor is at least one precursor selected from the group consisting of vinyltrimethylsilane, trimethylsilylacetylene, bistrimethylsilylacetylene, and divinyldimethylsilane.