Vapor-phase epitaxial growth method and vapor-phase epitaxy apparatus
A vapor phase epitaxial growth method using a vapor phase epitaxy apparatus having a chamber, a support structure holding thereon a substrate in the chamber, a first flow path supplying a reactant gas for film formation on the substrate and a second flow path for exhaust of the gas, said method includes rotating the substrate, supplying the reactant gas and a carrier gas to thereby perform vapor-phase epitaxial growth of a semiconductor film on the substrate, and during the vapor-phase epitaxial growth of the semiconductor film on the substrate, controlling process parameters to make said semiconductor film uniform in thickness, said process parameters including flow rates and concentrations of the reactant gas and the carrier gas, a degree of vacuum within said chamber, a temperature of the substrate, and a rotation speed of said substrate.
1. A vapor phase epitaxial growth method using a vapor phase epitaxy apparatus having a chamber, a support structure holding thereon a substrate in the chamber, a first flow path supplying a reactant gas for film formation on the substrate and a second flow path for exhaust of the gas, said method comprising:
rotating the substrate;
supplying the reactant gas and a carrier gas to thereby perform vapor-phase epitaxial growth of a semiconductor film on the substrate; and
during the vapor-phase epitaxial growth of the semiconductor film on the substrate, controlling process parameters to make said semiconductor film uniform in thickness, said process parameters including flow rates and concentrations of the reactant gas and the carrier gas, a degree of vacuum within said chamber, a temperature of the substrate, and a rotation speed of said substrate,
wherein said reactant gas is trichlorosilane,
wherein said carrier gas is hydrogen, and
wherein the trichlorosilane is adjusted to be equal to or less than 8 percent (%) in concentration within said chamber with an internal pressure of said chamber being set at 6.7 to 10.6×10 4 pascals (Pa) while setting the rotation speed of the substrate to 500 to 1,500 revolutions per minute (rpm) and the temperature of the substrate to 1,100 to 1,140 degrees centigrade (° C.) to thereby cause said semiconductor layer to grow at a growth rate of 8 micrometers per minute (μm/min) or greater, resulting in an in-plane thickness distribution of said semiconductor layer being less than or equal to 0.5%.
2. The method according to claim 1 ,
wherein said support structure has a first recess and a second recess at a bottom of the first recess, and
wherein said second recess has a depth being less than a thickness of said substrate to thereby uniformize gas flow on said substrate from said first gas flow path, whereby the in-plane thickness distribution of said semiconductor layer is within 0.5%.
3. The method according to claim 1 ,
wherein said support structure has a plurality of first raised portions as disposed around the substrate to constrain movement thereof in a substantially horizontal direction being identical to a surface of the substrate and a plurality of second raised portions at surface portions being in contact with said substrate to thereby support said substrate at top faces of the second raised portions, and
wherein the gases are flowed onto said substrate from said first flow path to ensure that the in-plane thickness distribution of said semiconductor layer is within 0.5%.
4. The method according to claim 1 , wherein said support structure has a first recess and a second recess at a bottom of the first recess, said second recess having a depth being less than a thickness of the substrate, a plurality of first raised portions as disposed around the substrate to constrain movement thereof in a substantially horizontal direction being identical to a surface of the substrate, and a plurality of second raised portions at surface portions to be in contact with said substrate for holding said substrate at top faces of said second raised portions, whereby gas flow on said substrate from said first flow path is made uniform so that the in-plane thickness distribution of said semiconductor layer is within 0.5%.
5. The method according to claim 4 , wherein the depth of said first recess is less than the thickness of said substrate.
6. The method according to claim 1 , wherein said support structure has a plurality of raised portions disposed around the substrate for constraining its movement in a substantially horizontal direction being identical to a surface of said substrate and a surface for holding said substrate as contacted with a back surface of said substrate.
7. The method according to claim 6 , wherein said raised portions extend toward a center of the substrate and are sized so that a length of each raised portion extending toward the center is more than twice a thickness of a film to be formed on the substrate surface by use of the reactant gas.