Plasma processing apparatus
View Patent ↗The invention provides a plasma processing apparatus aimed at suppressing the corrosion caused by reactive gas and heavy-metal contamination caused by plasma damage of components constituting the high-frequency electrode and gas supply unit. The plasma processing apparatus comprises a processing chamber 1 for subjecting a processing substrate 4 to plasma processing, gas supply means 17, 16 and 11 for feeding gas to the processing chamber 1 , and an antenna electrode 10 for supplying high-frequency radiation for discharging the gas to generate plasma, wherein the gas supply means includes a gas shower plate 11 having gas discharge holes on the surface exposed to plasma, and a portion of or a whole surface of the conductor 10 exposed to gas constituting the antenna-electrode side of the gas supply means is subjected to ceramic spraying containing no heavy metal to form a protecting film 12.
1. A plasma processing apparatus capable of subjecting a semiconductor device formed on a substrate to plasma processing using a corrosive gas, comprising:
a processing chamber for subjecting the semiconductor device formed on the substrate to plasma processing;
a gas supply means for supplying gas into the processing chamber;
a source of the corrosive gas, as the gas to be supplied into the processing chamber by the gas supply means; and
an antenna electrode made of an electrical conductor, for supplying high-frequency radiation to discharge the gas and to generate a plasma,
wherein the gas supply means includes a gas shower plate, having gas discharge holes, which discharges gas into the processing chamber,
wherein a space is formed between the electrical conductor of the antenna electrode, disposed at an antenna-electrode-side of the gas supply means, and the gas shower plate, into which space is supplied the corrosive gas,
wherein a whole of a surface of the electrical conductor of the antenna electrode, disposed at the antenna-electrode-side of the gas supply means, which would be exposed to the corrosive gas, is covered by a ceramic coating on the antenna electrode, formed by ceramic spraying, and on the ceramic coating is coated a layer of a polymer material, so as to prevent the corrosive gas from penetrating through the ceramic coating to the antenna electrode made of the electrical conductor,
wherein the gas in the space is supplied to the processing chamber through the gas shower plate,
wherein the gas shower plate is composed of quartz having a thickness of 3 mm or greater and 10 mm or smaller,
wherein the high-frequency radiation has a frequency ranging between 100 MHz and 500 MHz, and
wherein the space formed between the electrical conductor of the antenna electrode, disposed at the antenna-electrode-side of the gas supply means, and the gas shower plate, is a gap therebetween which is 0.5 mm or smaller.
2. The plasma processing apparatus according to claim 1 , wherein the gas discharge holes are formed at angles of 5 to 45 degrees to the direction of plate thickness of the gas shower plate.
3. The plasma processing apparatus according to claim 1 , wherein a base material of the antenna electrode is aluminum or an alloy thereof, and wherein an anodized aluminum coating is provided on the electrical conductor of the antenna electrode, between the electrical conductor and the ceramic coating formed by the ceramic spraying.
4. The plasma processing apparatus according to claim 1 , wherein the ceramic coating formed by the ceramic spraying includes at least one element selected from the group consisting of Al, Si and Y.
5. The plasma processing apparatus according to claim 4 , wherein ceramic material of the ceramic coating is selected from the group consisting of Al 2 O 3 , SiC and Si 3 N 4 .
6. The plasma processing apparatus according to claim 1 , wherein said gas shower plate is a body of quartz, exposed to said space.
7. The plasma processing apparatus according to claim 6 , wherein said body of quartz is a single body, and is also exposed to said processing chamber.
8. The plasma processing apparatus according to claim 1 , wherein the processing chamber is provided therein with an electrode for supporting the semiconductor device, and wherein the gas shower plate is provided between the electrode for supporting the semiconductor device and the antenna electrode.