A method for preventing contamination of a base plate having a step of, after producing polycrystalline silicon in a reactor having the base plate and a lid covering the base plate, removing the lid from the base plate; and a step of isolating space including the base plate by an isolation device.

A semiconductor silicon wafer manufacturing method is provided, where P aggregate defects and SF in an epitaxial layer can be suppressed. A silicon wafer substrate cut from a monocrystal ingot is doped with phosphorus and has a resistivity of 1.05 mΩ.Math.cm or less and a concentration of solid-solution oxygen of 0.9×10.sup.18 atoms/cm.sup.3. The method includes steps of mirror-polishing substrates and heat treatment, where after the mirror-polishing step, the substrate is kept at a temperature from 700° C. to 850° for 30 to 120 minutes, then after the temperature rise, kept at a temperature from 100° C. to 1250° for 30 to 120 minutes, and after cooling, kept at a temperature from 700° C. to 450° C. for less than 10 minutes as an experience time. The heat treatment step is performed in a mixture gas of hydrogen and argon. The method includes an epitaxial layer deposition step to a thickness of 1.3 μm to 10.0 μm.

A semiconductor silicon wafer manufacturing method is provided, where P aggregate defects and SF in an epitaxial layer can be suppressed. A silicon wafer substrate cut from a monocrystal ingot is doped with phosphorus and has a resistivity of 1.05 mΩ.Math.cm or less and a concentration of solid-solution oxygen of 0.9×10.sup.18 atoms/cm.sup.3. The method includes steps of mirror-polishing substrates and heat treatment, where after the mirror-polishing step, the substrate is kept at a temperature from 700° C. to 850° for 30 to 120 minutes, then after the temperature rise, kept at a temperature from 100° C. to 1250° for 30 to 120 minutes, and after cooling, kept at a temperature from 700° C. to 450° C. for less than 10 minutes as an experience time. The heat treatment step is performed in a mixture gas of hydrogen and argon. The method includes an epitaxial layer deposition step to a thickness of 1.3 μm to 10.0 μm.

Provided are a method of selectively etching a film primarily containing Si, such as polycrystalline silicon (Poly-Si), single crystal silicon (single crystal Si), or amorphous silicon (a-Si) as well as a method for cleaning by removing a Si-based deposited and/or attached matter inside a sample chamber of a film forming apparatus, such as a chemical vapor deposition (CVD) apparatus, without damaging the apparatus interior. By simultaneously introducing a monofluoro interhalogen gas (XF, where X is any of Cl, Br, and I) and nitric oxide (NO) into an etching or a film forming apparatus, followed by thermal excitation, it is possible to selectively and rapidly etch a Si-based film, such as Poly-Si, single crystal Si, or a-Si, while decreasing the etching rate of SiN and/or SiO.sub.2. It is also possible to perform cleaning by removing a Si-based deposited and/or attached matter inside a film forming apparatus, such as a CVD apparatus, without damaging the apparatus interior.

Provided are a method of selectively etching a film primarily containing Si, such as polycrystalline silicon (Poly-Si), single crystal silicon (single crystal Si), or amorphous silicon (a-Si) as well as a method for cleaning by removing a Si-based deposited and/or attached matter inside a sample chamber of a film forming apparatus, such as a chemical vapor deposition (CVD) apparatus, without damaging the apparatus interior. By simultaneously introducing a monofluoro interhalogen gas (XF, where X is any of Cl, Br, and I) and nitric oxide (NO) into an etching or a film forming apparatus, followed by thermal excitation, it is possible to selectively and rapidly etch a Si-based film, such as Poly-Si, single crystal Si, or a-Si, while decreasing the etching rate of SiN and/or SiO.sub.2. It is also possible to perform cleaning by removing a Si-based deposited and/or attached matter inside a film forming apparatus, such as a CVD apparatus, without damaging the apparatus interior.

There is provided a technique that includes: (a) forming a silicon seed layer on a substrate by performing a cycle a predetermined number of times, the cycle including non-simultaneously performing: (a1) supplying a first gas containing halogen and silicon to the substrate; and (a2) supplying a second gas containing hydrogen to the substrate; and (b) forming a film containing silicon on the silicon seed layer by supplying a third gas containing silicon to the substrate, wherein a pressure of a space in which the substrate is located in (a2) is set higher than a pressure of the space in which the substrate is located in (a1).

There is provided a technique that includes: (a) forming a silicon seed layer on a substrate by performing a cycle a predetermined number of times, the cycle including non-simultaneously performing: (a1) supplying a first gas containing halogen and silicon to the substrate; and (a2) supplying a second gas containing hydrogen to the substrate; and (b) forming a film containing silicon on the silicon seed layer by supplying a third gas containing silicon to the substrate, wherein a pressure of a space in which the substrate is located in (a2) is set higher than a pressure of the space in which the substrate is located in (a1).

Provided is a susceptor which makes it possible to increase the circumferential flatness uniformity of an epitaxial layer of an epitaxial silicon wafer. A susceptor 100 is provided with a concave counterbore portion on which a silicon wafer W is placed, and the radial distance L between the center of the susceptor and an opening edge of the counterbore portion varies at 90° periods in the circumferential direction. Meanwhile, when the angle at which the radial distance L is minimum is 0°, the radial distance L is a minimum value L.sub.1 at 90°, 180°, and 270°; and the radial distance L is a maximum value L.sub.2 at 45°, 135°, 225°, and 315°. Accordingly, the pocket width L.sub.p also varies in conformance with the variations of the radial distance L. The opening edge 110C describes four elliptical arcs being convex radially outward when the susceptor 100 is viewed from above.

A method and apparatus for reducing as-deposited and metastable defects relative to amorphous silicon (a-Si) thin films, its alloys and devices fabricated therefrom that include heating an earth shield positioned around a cathode in a parallel plate plasma chemical vapor deposition chamber to control a temperature of a showerhead in the deposition chamber in the range of 350° C. to 600° C. An anode in the deposition chamber is cooled to maintain a temperature in the range of 50° C. to 450° C. at the substrate that is positioned at the anode. In the apparatus, a heater is embedded within the earth shield and a cooling system is embedded within the anode.

A method and apparatus for reducing as-deposited and metastable defects relative to amorphous silicon (a-Si) thin films, its alloys and devices fabricated therefrom that include heating an earth shield positioned around a cathode in a parallel plate plasma chemical vapor deposition chamber to control a temperature of a showerhead in the deposition chamber in the range of 350° C. to 600° C. An anode in the deposition chamber is cooled to maintain a temperature in the range of 50° C. to 450° C. at the substrate that is positioned at the anode. In the apparatus, a heater is embedded within the earth shield and a cooling system is embedded within the anode.