Plasma processing method and apparatus
In a state that a plate-shaped insulator is disposed adjacent to a plate-shaped electrode, a discharge gas containing an inert gas is supplied to a vicinity of a processing object from one gas exhaust port located nearer from the plate-shaped electrode, out of at least two-line gas exhaust ports which are disposed around the plate-shaped electrode and which are formed so as to be surrounded by the plate-shaped insulator and moreover which are different in distance to the plate-shaped electrode from each other, while a discharge control gas is supplied from the other gas exhaust port to the vicinity of the processing object. Simultaneously with the supply of the gases, electric power is supplied to the plate-shaped electrode or the processing object, by which plasma processing of the processing object is carried out. Thus, plasma processing method and apparatus capable of processing for desired fine linear portions with high precision are provided.
1. A plasma processing apparatus comprising:
a plate-shaped electrode;
a plate-shaped insulator placed at a position where the plate-shaped insulator is adjacent to the plate-shaped electrode and where the plate-shaped insulator does not cover a part of a surface of the plate-shaped electrode confronting a processing object;
an electric power supply unit for supplying electric power to the plate-shaped electrode or the processing object;
a discharge-gas supply unit for supplying a discharge gas containing an inert gas to one gas exhaust port located nearer from the plate-shaped electrode, out of at least two-line gas exhaust ports which are disposed near the plate-shaped electrode and which are different in distance to the plate-shaped electrode from each other; and
a discharge-control gas supply unit for supplying a discharge control gas, which is larger in discharge-starting voltage than the inert gas, to one gas exhaust port located farther from the plate-shaped electrode, out of the at least two-line gas exhaust ports which are disposed near the plate-shaped electrode and which are different in distance to the plate-shaped electrode from each other.
2. The plasma processing apparatus according to claim 1 , wherein at least a surface of the plate-shaped electrode confronting the processing object has a taper portion.
3. The plasma processing apparatus according to claim 1 , wherein a line-direction opening length of the gas exhaust port for the discharge gas located nearer from the plate-shaped electrode is smaller than a line-direction opening length of the gas exhaust port for the discharge control gas located farther from the plate-shaped electrode.
4. The plasma processing apparatus according to claim 1 , wherein a part of a surface of the plate-shaped insulator confronting the processing object has a taper portion.
5. The plasma processing apparatus according to claim 1 , wherein a distance between the processing object and the gas exhaust port for the discharge control gas located farther from the plate-shaped electrode is smaller than a distance between the processing object and the gas exhaust port for the discharge gas located nearer from the plate-shaped electrode.
6. The plasma processing apparatus according to claim 5 , wherein assuming that the distance between the processing object and the gas exhaust port for the discharge control gas located farther from the plate-shaped electrode is m and that the distance between the processing object and the gas exhaust port for the discharge gas located nearer from the plate-shaped electrode is k, then it holds that
0 mm<k−m≦1 mm.