Plasma generator and method of using same
A plasma generator and a method of using the same are proposed. The disclosed relates to a plasma generator and a method of using the same capable of improving the uniformity of plasma used in a semiconductor manufacturing process and forming fine patterns and patterns having a high aspect ratio by precisely controlling ion energy. The plasma generator includes a vacuum chamber, a source electrode provided in the vacuum chamber, a bias electrode provided to correspond to the source electrode in the vacuum chamber and on which a substrate seated thereon, a shower head unit provided on a lower part of the source electrode to supply reaction gas to a plasma space above the substrate, an RF power supply unit for applying RF power to the source electrode, and a bias power supply unit connected to the bias electrode to apply bias power.
1 . A plasma generator comprising:
a vacuum chamber;
a source electrode provided in the vacuum chamber;
a bias electrode provided to correspond to the source electrode in the vacuum chamber and on which a substrate is seated;
a shower head unit provided on a lower part of the source electrode to supply reaction gas to a plasma space above the substrate;
an RF power supply unit for applying RF power to the source electrode; and
a bias power supply unit connected to the bias electrode to apply bias power,
wherein the shower head unit is configured to control the reaction gas supplied to a center zone and an edge zone of the substrate,
wherein the bias power supply unit comprises a direct current (DC) pulse generation module for generating a DC bias pulse, and the DC pulse generation module comprising:
a pulse generator for generating an alternating current (AC) pulse;
a first rectifier for performing half-wave rectification of the pulse generated by the pulse generator to generate a positive (+) DC pulse; and
a second rectifier for performing half-wave rectification of the pulse generated by the pulse generator to generate a negative (−) DC pulse.
2 . The plasma generator of claim 1 , wherein the shower head unit comprises:
a first shower head unit having a first gas supply section provided with a first gas to be introduced to the edge zone of the substrate and a first gas inlet through which the first gas provided in the first gas supply section flows toward the edge zone of the substrate; and
a second shower head unit having a second gas supply section provided with a second gas to be introduced to the center zone of the substrate and a second gas inlet through which the second gas provided in the second gas supply section flows to the center zone of the substrate.
3 . The plasma generator of claim 2 , wherein the second shower head unit further comprises:
a third gas supply section provided with a partition for dividing an internal space of the second shower head unit into a center zone and an edge zone, and having a third gas inlet through which the first gas provided in the third gas supply section flows to the edge zone of the substrate.
4 . The plasma generator of claim 2 , wherein the source electrode comprises:
a first gas supply port for injecting the first gas;
a second gas supply port for injecting the second gas; and
a first baffle for diffusing the first gas injected through the first gas supply port to the first gas supply section.
5 . The plasma generator of claim 4 , wherein the first gas supply port is a contact point to which the RF power is applied.
6 . The plasma generator of claim 5 , wherein the first baffle is provided at a center of the source electrode.
7 . The plasma generator of claim 4 , wherein the first shower head unit further comprises:
a second baffle for diffusing the second gas supplied through the second gas supply port into the second gas supply section.
8 . The plasma generator of claim 7 , wherein the second baffle is provided at a center of the first shower head unit.
9 . The plasma generator of claim 1 , further comprising:
a bias matcher for controlling an impedance connected in parallel to the DC pulse generation module; and
an RF bias.
10 . A method of etching a substrate by using the plasma generator of claim 1 , the method comprising:
a first step S 10 of injecting gas;
a second step S 20 of controlling pressure in a vacuum chamber;
a third step S 30 of applying RF power by operating an RF power supply unit;
a fourth step S 40 of applying a negative (−) DC pulse to a bias power supply unit by using a DC pulse generation module; and
a fifth step S 50 of applying a positive (+) DC pulse to the bias power supply unit by using the DC pulse generation module.