Plasma processing apparatus and manufacturing method of semiconductor device
A plasma processing apparatus according to an embodiment includes: an upper electrode that supplies a process gas into a processing container; and an exhaust unit that exhausts the inside of the processing container, in which the upper electrode includes: a diffusion portion that is interposed between the first and second surfaces, the diffusion portion in which the process gas is diffused; a plurality of gas supply holes that supplies the process gas into the processing container, the plurality of gas supply holes arranged on the first surface; and a plurality of gas exhaust holes arranged on the second surface, the plurality of gas exhaust holes being connected to the exhaust unit, and the total area of the plurality of gas exhaust holes is larger than the total area of the plurality of gas supply holes.
1 . A manufacturing method of a semiconductor device, the manufacturing method comprising:
loading a substrate into a processing container in which the substrate is processed;
placing the substrate on a lower electrode facing an upper electrode in the processing container;
supplying a first process gas from a plurality of gas supply holes arranged on a first surface of the upper electrode, the first surface facing the lower electrode;
generating plasma of the first process gas in the processing container during a first period by supplying electric power to at least one of the upper electrode and the lower electrode;
stopping generation of the plasma and supply of the first process gas after the first period has elapsed;
supplying a second process gas from the plurality of gas supply holes arranged on the first surface;
generating plasma of the second process gas in the processing container during a second period by supplying electric power to at least one of the upper electrode and the lower electrode; and
after the generation of the plasma and the supply of the first process gas are stopped, and before the supply of the second process gas, exhausting the first process gas in a diffusion portion via a plurality of gas exhaust holes arranged on a second surface on an opposite side to the first surface and separated from the first surface by the diffusion portion, the diffusion portion in which the first process gas is diffused,
wherein
when the first process gas in the diffusion portion is exhausted,
exhausting an inside of the processing container in parallel with the exhaust of the first process gas in the diffusion portion while performing control in such a manner that a pressure in the diffusion portion is lower than a pressure in the processing container.
2 . The manufacturing method of a semiconductor device according to claim 1 ,
wherein a total area of the plurality of gas exhaust holes is larger than a total area of the plurality of gas supply holes.
3 . The manufacturing method of a semiconductor device according to claim 1 ,
wherein an average diameter of the plurality of gas exhaust holes is larger than an average diameter of the plurality of gas supply holes.
4 . The manufacturing method of a semiconductor device according to claim 1 ,
wherein the upper electrode further includes a partition wall that partitions the diffusion portion into a plurality of regions, and
the plurality of gas exhaust holes is dispersedly arranged at positions corresponding to the plurality of regions on the second surface.
5 . The manufacturing method of a semiconductor device according to claim 1 , the manufacturing method comprising:
when the first process gas in the diffusion portion is exhausted, exhausting the first process gas by opening a valve provided between the plurality of gas exhaust holes and an exhaust unit that exhausts the inside of the processing container.
6 . The manufacturing method of a semiconductor device according to claim 5 , the manufacturing method comprising:
stopping the exhaust of the diffusion portion by closing the valve after exhausting the first process gas and before supplying the second process gas.
7 . The manufacturing method of a semiconductor device according to claim 1 , the manufacturing method comprising:
repeating plasma generation of the first process gas and plasma generation of the second process gas a plurality of times; and
when generating the plasma of the first process gas after generating the plasma of the second process gas, exhausting the second process gas in the diffusion portion via the plurality of gas exhaust holes after the second period has elapsed and the generation of the plasma and the supply of the second process gas are stopped and before the first process gas is supplied.
8 . The manufacturing method of a semiconductor device according to claim 7 , the manufacturing method comprising:
when the second process gas in the diffusion portion is exhausted, exhausting the second process gas by opening a valve provided between the plurality of gas exhaust holes and an exhaust unit that exhausts the inside of the processing container.
9 . The manufacturing method of a semiconductor device according to claim 8 , the manufacturing method comprising:
stopping the exhaust of the diffusion portion by closing the valve after exhausting the second process gas and before supplying the first process gas.
10 . The manufacturing method of a semiconductor device according to claim 7 , the manufacturing method comprising:
etching a first layer on the substrate with the plasma of the first process gas; and
etching a second layer on the substrate with the plasma of the second process gas.
11 . The manufacturing method of a semiconductor device according to claim 10 , the manufacturing method comprising:
as the first process gas, selecting a gas species with which the first layer is selectively etched with respect to the second layer by the plasma of the first process gas; and
as the second process gas, selecting a gas species with which the second layer is selectively etched with respect to the first layer by the plasma of the second process gas.