GAS SUPPLY APPARATUS
A gas ejector of a gas supply apparatus includes a nozzle portion. The opening of a first-stage restricting cylinder constituting the nozzle portion has a circular cross-sectional shape with a diameter r 1 . A second-stage restricting cylinder is continuously formed with the first-stage restricting cylinder along a Z direction. The opening of the second-stage restricting cylinder has a circular cross-sectional shape with a diameter r 2 , and supplies a source gas supplied from the first-stage restricting cylinder to a low-vacuum processing chamber below. At this time, the diameter r 2 is set to satisfy “r 2 >r 1”.
1 : A gas supply apparatus comprising:
a mounting portion for mounting a substrate to be processed; and
a gas ejector which is provided above said mounting portion and supplies gas from a processing chamber having an opening on a bottom surface to said substrate to be processed, wherein
said gas ejector includes:
a primary accommodating chamber which temporarily accommodates gas supplied from a gas supply port;
said processing chamber; and
a nozzle portion which is provided between said primary accommodating chamber and said processing chamber,
said nozzle portion has:
a first restricting cylinder whose opening has a circular cross-sectional shape with a first diameter in plan view, and which supplies the gas in said primary accommodating chamber downward; and
a second restricting cylinder whose opening has a circular cross-sectional shape with a second diameter in plan view, and which supplies the gas supplied from said first restricting cylinder to said processing chamber,
said first diameter is set such that pressure difference between said primary accommodating chamber and said processing chamber is not less than a predetermined pressure ratio, and
said second diameter is set to be longer than said first diameter.
2 : The gas supply apparatus according to claim 1 , wherein
said predetermined pressure ratio is 30 times,
said first diameter of said first restricting cylinder is set to be not greater than 2 mm in diameter and a formation length of said first restricting cylinder is set to be not greater than 2 mm, and
pressure difference between pressure in said primary accommodating chamber and pressure in said processing chamber is set to be not less than 30 times.
3 : The gas supply apparatus according to claim 1 ,
wherein said second diameter of said second restricting cylinder is set within 30 mm in diameter.
4 : The gas supply apparatus according claim 1 , wherein
said nozzle portion further includes a third restricting cylinder whose opening has a circular cross-sectional shape with a third diameter in plan view, and which supplies the gas supplied from said second restricting cylinder to said processing chamber, and
said third diameter is longer than said second diameter.
5 : The gas supply apparatus according to claim 1 ,
wherein said second restricting cylinder in said nozzle portion is formed into a hemispherical shape such that said second diameter becomes longer as said second restricting cylinder approaches said processing chamber.
6 : The gas supply apparatus according to claim 1 ,
wherein a gas contact region which is a region to be brought into contact with gas in said gas ejector is formed to include one of quartz and an alumina material as a constituent material.
7 : The gas supply apparatus according to claim 1 ,
wherein said gas ejector is heated to not lower than 100° C. so as to supply heated gas to said substrate to be processed.
8 : The gas supply apparatus according to claim 1 ,
wherein the gas supplied from said gas supply port is gas containing at least nitrogen, oxygen, fluorine, and hydrogen.
9 : The gas supply apparatus according to claim 1 ,
wherein the gas supplied from said gas supply port is a precursor gas.
10 : The gas supply apparatus according to claim 1 ,
wherein a gas flow rate of the gas supplied from said gas supply port is controlled such that pressure in said primary accommodating chamber is set to be not higher than atmospheric pressure and not lower than 10 kPa.
11 : The gas supply apparatus according to claim 1 ,
wherein said nozzle portion includes a plurality of nozzle portions.
12 : The gas supply apparatus according to claim 11 ,
wherein said first diameters of said first restricting cylinders in said plurality of nozzle portions are set to different values.
13 : The gas supply apparatus according to claim 1 , further comprising:
a gas ionization unit which is provided near a boundary region between said primary accommodating chamber and said nozzle portion, and produces one of an ionized gas and a radicalized gas by ionizing the gas supplied from said gas supply port.
14 : The gas supply apparatus according to claim 13 , wherein
said gas ionization unit has a first electrode and a second electrode provided so as to face each other and has a discharge space between said first electrode and said second electrode, and at least one of said first electrode and said second electrode has a dielectric on a surface forming said discharge space,
said first restricting cylinder is formed of a through hole formed in said second electrode, and
one of said ionized gas and said radicalized gas is supplied to said processing chamber, the one of said ionized gas and said radicalized gas being obtained by applying an alternating voltage between said first electrode and said second electrode, and generating dielectric-barrier discharge in said discharge space.
15 : The gas supply apparatus according to claim 13 , wherein
said nozzle portion includes a plurality of nozzle portions, and
said gas ionization unit includes a plurality of gas ionization units provided correspondingly to said plurality of nozzle portions, and said plurality of gas ionization units are independently controllable.