Method for forming insulation film using non-halide precursor having four or more silicons
A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), includes: (i) adsorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space; (ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the reactant; and (iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and (iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate.
1. A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), which comprises:
(i) adsorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space, thereby producing a precursor-adsorbed substrate;
(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant, said oxygen-free reactant consisting of NH 3 or a combination of He and N 2 ; and
(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and
(iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate wherein the insulation film is constituted by SiN or SiCN.
2. The method according to claim 1 , further comprising continuously supplying an inactive gas to the reaction space through the cycle.
3. The method according to claim 1 , wherein the oxygen-free reactant is supplied continuously through the cycle.
4. The method according to claim 1 , further comprising purging the reaction space between steps (i) and (ii) and between step (ill) and subsequent step (i) in the next cycle.
5. The method according to claim 1 , wherein the non-excited non-halide precursor is a cyclic compound.
6. The method according to claim 5 , wherein the non-excited non-halide precursor is cyclopentasilane.
7. The method according to claim 1 , wherein the non-excited non-halide precursor is a non-cyclic compound.
8. The method according to claim 7 , wherein the non-excited non-halide precursor is tris(trimethylsilyl)silane.
9. The method according to claim 1 , wherein the non-excited non-halide precursor is oxygen-free and nitrogen-free.
10. The method according to claim 1 , wherein the substrate is controlled continuously at a temperature lower than about 300° C.
11. The method according to claim 1 , wherein the substrate has patterned recesses on its surface, and the insulation film is deposited on the surface.
12. The method according to claim 11 , wherein the insulation film has a sidewall coverage of about 90% or higher.
13. A method of forming an insulation film on a semiconductor substract by plasma enhanced atomic layer deposition (PEALD), which comprises:
(i) absorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space, thereby producing a precursor-adsorbed substrate;
(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant; and
(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and
(iv) repeating steps (i) to (iii) as a cycle, thereby depositing and insulation film on the substrate,
said method further comprising purging the reaction space between steps (i) and (ii) and between step (iii) and subsequent step (i) in the next cycle, and further comprising applying RF power in a pulse immediately prior to step (ii) after step (i), and supplying another reactant while applying RF power immediately prior to step (ii) after step (i).
14. The method according to claim 13 , wherein the another reactant is a rare gas.
15. A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), which comprises:
(i) absorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in reaction space, thereby producing a precursor-absorbed substrate;
(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant, said oxygen-free reactant consisting of He, H 2 , or a mixture of He and H 2 ; and
(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and
(iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate,
wherein the insulation film is constituted by amorphous silicon.