Plasma etching apparatus and plasma etching method

Abstract

A plasma processing apparatus includes a vacuum processing chamber, a plasma generating unit having a first power source, a gas supply unit, a lower electrode having a sample table surface for holding a sample in the vacuum processing chamber, and a vacuum pumping unit. The apparatus further includes a plate disposed at a position opposed to the sample table surface, a disc electricity conductor disposed in contact with the plate, a second power source for applying an RF frequency bias power to the disc electricity conductor, and a unit for controlling a temperature of the plate to a predetermined value. The plate is made of silicon or carbon at high purity, and the disc electricity conductor and the plate have a plurality of holes for introducing processing gas from the gas supply unit into the vacuum processing chamber.

1 . A plasma processing apparatus having a vacuum processing chamber, a plasma generating unit having a first power source, a gas supply unit for supplying a processing gas to the vacuum processing chamber, a lower electrode having a sample table surface for holding a sample to be processed in the vacuum processing chamber, and a vacuum pumping unit for depressurizing the vacuum processing chamber, wherein the apparatus further comprises: 
 a plate disposed at a position opposed to the sample table surface and facing a plasma in the vacuum processing chamber;    a disc electricity conductor disposed in contact with a side of the plate which is opposite to another side of the plate which faces the plasma;    a second power source for applying an RF frequency bias power to the disc electricity conductor; and    a unit for controlling a temperature of the plate to a predetermined value;    wherein the plate is made of one of silicon and carbon at high purity; and    wherein the disc electricity conductor and the plate have a plurality of holes for introducing the processing gas supplied from the gas supply unit into the vacuum processing chamber, respectively.    
   
   
       2 . A plasma processing apparatus according to  claim 1 , wherein the distance between a lower surface at the another side of the plate which faces the plasma and the sample on the sample table surface is from 30 mm to 150 mm.  
   
   
       3 . A plasma processing apparatus according to  claim 1 , wherein the unit for the controlling the temperature of the plate to the predetermined value has a heat transfer medium that circulates within the disc electricity conductor.  
   
   
       4 . A plate for use in a plasma processing apparatus having a vacuum processing chamber, a plasma generating unit having a disc electricity conductor applied with a first power source, a gas supply unit for supplying a processing gas to the vacuum processing chamber, an electrode having a sample table surface for holding a sample to be processed in the vacuum processing chamber, and a vacuum pumping unit depressurizing the vacuum processing chamber; 
 wherein the plate is made of one of silicon and carbon at high purity;    wherein the plate is disposed at a position opposed to the sample table surface and facing a plasma in the vacuum processing chamber, with the disc electricity conductor being disposed in contact with a side of the plate which is opposite to another side of the plate which faces the plasma;    wherein the plate has a plurality of holes for introducing the processing gas supplied from the gas supply unit into the vacuum processing chamber;    wherein the plate is applied with an RF frequency bias power by way of the disc electricity conductor from a second power source; and    wherein the plate has a unit for controlling a temperature of the plate to a predetermined value.