Method of manufacturing semiconductor device and non-transitory computer-readable recording medium
Described herein is a technique capable of improving electrical characteristics of a polysilicon film while suppressing damage to an underlying silicon oxide film. According to the technique described herein, there is provided a there is provided a method of manufacturing a semiconductor device, including: (a) preparing a substrate including a silicon oxide film and a polysilicon film formed on the silicon oxide film, wherein the polysilicon film includes a contact surface contacting the silicon oxide film and an exposed surface facing the contact surface; and (b) supplying a reactive species generated by plasma excitation of a gas containing hydrogen and oxygen to the exposed surface of the polysilicon film.
1. A method of manufacturing a semiconductor device, comprising:
(a) preparing a substrate comprising a first silicon oxide film and a polysilicon film formed on the first silicon oxide film, wherein the polysilicon film comprises a contact surface contacting the first silicon oxide film and an exposed surface facing the contact surface;
(b) supplying a reactive species generated by plasma excitation of a predetermined gas containing hydrogen and oxygen to the exposed surface of the polysilicon film such that: the reactive species supplied to the exposed surface of the polysilicon film reaches the contact surface and reacts with the polysilicon film and the first silicon oxide film; and hydrogen atoms contained in the reactive species are added to the polysilicon film, wherein the first silicon oxide film and the polysilicon film are formed on a side surface of an inner wall of a trench structure or a cylindrical structure formed on the substrate in a manner that the first silicon oxide film and the polysilicon film are sequentially stacked toward a center of the trench structure or the cylindrical structure; and
(c) forming a second silicon oxide film on the polysilicon film after the polysilicon film is processed by the plasma.
2. A non-transitory computer-readable recording medium storing a program that causes, by a computer, a substrate processing apparatus to perform:
(a) preparing a substrate comprising a first silicon oxide film and a polysilicon film formed on the first silicon oxide film, wherein the polysilicon film comprises a contact surface contacting the first silicon oxide film and an exposed surface facing the contact surface;
(b) supplying a reactive species generated by plasma excitation of a predetermined gas containing hydrogen and oxygen to the exposed surface of the polysilicon film such that: the reactive species supplied to the exposed surface of the polysilicon film reaches the contact surface and reacts with the polysilicon film and the first silicon oxide film; and hydrogen atoms contained in the reactive species are added to the polysilicon film, wherein the first silicon oxide film and the polysilicon film are formed on a side surface of an inner wall of a trench structure or a cylindrical structure formed on the substrate in a manner that the first silicon oxide film and the polysilicon film are sequentially stacked toward a center of the trench structure or the cylindrical structure; and
(c) forming a second silicon oxide film on the polysilicon film after the polysilicon film is processed by the plasma.
3. The method of claim 1 , wherein the predetermined gas comprises a mixed gas of a hydrogen-containing gas and an oxygen-containing gas.
4. The method of claim 1 , wherein the predetermined gas comprises a mixed gas of a hydrogen gas and an oxygen gas.
5. The method of claim 1 , wherein a stacked structure is formed on the substrate by stacking a control gate, a first insulating film, a trap layer, the silicon oxide film serving as a second insulating film, and the polysilicon film serving as a channel part.
6. The method of claim 1 , wherein a thickness of at least a part of the polysilicon film is equal to or less than 7 nm.
7. The method of claim 1 , further comprising:
(c) supplying a nitrogen reactive species generated by exciting a gas containing nitrogen to the exposed surface of the polysilicon film after performing (b) such that the nitrogen reactive species reacts with the exposed surface of the polysilicon film and a silicon nitride film is formed on the polysilicon film.
8. The method of claim 1 , wherein (a) comprises (a-1) loading the substrate into a process chamber having a plasma generation space where the predetermined gas is excited by plasma and placing the substrate at a position below a lower end of a coil provided at an outer peripheral portion of the process chamber, an electrical length of the coil being equal to an integral multiple of a wavelength of a high frequency power applied to the coil, and
wherein (b) comprises:
(b-1) supplying the predetermined gas to the plasma generation space;
(b-2) exciting the predetermined gas in the plasma generation space by applying the high frequency power to the coil; and
(b-3) controlling a frequency of the high frequency power applied to the coil so as to maintain a resonance state of the coil while (b-2) is performed.
9. The method of claim 1 , wherein a ratio of hydrogen atoms to oxygen atoms in the predetermined gas ranges from 5:95 to 95:5.
10. The method of claim 4 , wherein a volume ratio of the hydrogen gas and the oxygen gas in the mixed gas ranges from 5:95 to 95:5.
11. The method of claim 1 , wherein a defect density of the polysilicon film is decreased after performing (b) compared with a defect density of the polysilicon film before performing (b).
12. The method of claim 1 , wherein a size of polysilicon particles constituting the polysilicon film is increased after performing (b) compared with a size of polysilicon particles constituting the polysilicon film before performing (b).
13. The method of claim 1 , wherein an electron mobility in the polysilicon film is increased after performing (b) compared with an electron mobility in the polysilicon film before performing (b).
14. The method of claim 1 , wherein in (b), the reactive species are supplied to the exposed surface of the polysilicon film such that oxygen atoms contained in the reactive species reacts with the silicon oxide film and suppresses the hydrogen atoms contained in the reactive species from being added to the silicon oxide film.
15. The method of claim 1 , wherein in (b), the reactive species are supplied to the exposed surface of the polysilicon film such that oxygen atoms contained in the reactive species reacts with the silicon oxide film and suppresses the hydrogen atoms contained in the reactive species from desorbing oxygen atoms in the silicon oxide film.
16. The method of claim 1 , wherein the predetermined gas comprises an H 2 O gas.
17. The method of claim 1 , wherein the predetermined gas consists of a mixed gas of a hydrogen gas, an oxygen gas, and an argon gas.