Target supply apparatus, control system, control apparatus and control circuit thereof

• US 8,581,220 B2
• Filed: 12/23/2009
• Issued: 11/12/2013
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: CKD Corporation, Gigaphoton, Inc. (Komatsu)
• Original Assignee: CDK Corporation, Gigaphoton, Inc. (Komatsu)
• Inventors: Ishihara, Takanobu, Itafuji, Hiroshi
• Primary Examiner(s): Nguyen, Dinh Q
• Application Number:
  US12/646,025
• Publication Number:
  US 20100213275A1
• Time in Patent Office: 1,420 Days
• Field of Search: 250/504.R, 376/195, 376/189, 376/198, 376/201, 239/690, 239/102.2
• US Class Current: 250/504.R
• CPC Class Codes: G03F 7/70033 by plasma extreme ultraviolet [EUV] sources
• CPC Class Codes: H05G 2/003 the plasma being generated from a material in a liquid or gas state
• CPC Class Codes: H05G 2/006 details of the ejection system, e.g. constructional details of the nozzle
• CPC Class Codes: H05G 2/008 involving an energy-carrying beam in the process of plasma generation

Abstract

A target supply apparatus includes a tank for storing a liquid target material, a nozzle for outputting the liquid target material in the tank, and a gas supply source for supplying gas into the tank, and controls a gas pressure inside the tank with a pressure of the gas supplied from the gas supply source which is provided with a pressure regulator. The target supply apparatus also includes a pressure-decrease gas passage of which one end is connected to the tank and the other end forms an exhaust port, a pressure-decrease valve provided on the pressure-decrease gas passage, and a controller for controlling open/close of the pressure-decrease valve. The controller, when the target material is caused not to output from the nozzle, opens the pressure-decrease valve and decreases the pressure inside the tank.

Claims

1. A target supply apparatus comprising:

a tank for storing a liquid target material;

a nozzle for outputting the liquid target material in the tank; and

a gas supply source for supplying gas into the tank,

the target supply apparatus controlling a gas pressure inside the tank with a pressure of the gas supplied from the gas supply source provided with a pressure regulator, and further comprising;

a pressure-decrease gas passage of which one end is connected to the tank and the other end forms an exhaust port;

a pressure-decrease valve provided in the pressure-decrease gas passage;

a controller for controlling open/close of the pressure-decrease valve;

a pressure-increase gas passage connecting between the gas supply source and the tank, the pressure regulator being provided in the pressure-increase gas passage;

a pressure-increase valve provided in the pressure-increase gas passage between the pressure regulator and the tank;

a gas passage connected at one end thereof to between the pressure regulator and the pressure-increase valve;

a storage tank connected to the other end of the gas passage and having a large capacity as compared with the capacity of the tank; and

a valve provided in the gas passage, wherein

one end of the pressure-decrease gas passage is connected to the pressure-increase gas passage between the pressure-increase valve and the tank,

the controller, when the target material is to be output from the nozzle, opens the pressure-increase valve and closes the pressure-decrease valve, to thereby increase the pressure inside the tank, and decreases the pressure inside the tank, when the target material is not to be output from the nozzle, by closing the pressure-increase valve and opening the pressure decrease valve, and

the controller closes the pressure-increase valve and opens the valve, to thereby increase the pressure inside the storage tank, and when the pressure inside the tank is to be increased, opens the pressure-increase valve, to thereby increase the pressure inside the tank with a pressure increasing assist by the storage tank.

2. The target supply apparatus according to claim 1, wherein the target material is caused to output from the nozzle provided at the tank by the pressure inside the tank.

3. The target supply apparatus according to claim 1, further comprising:

an electrode provided in a position opposite to the nozzle, wherein

the target material is caused to output from the nozzle by the pressure inside the tank and an electrostatic attractive force produced caused by applying a potential to the electrode.

4. The target supply apparatus according to claim 1, further comprising:

a first gas passage connected to the pressure-decrease gas passage on the side of the tank from the pressure-decrease valve;

a vacuum pump connected to the other end of the first gas passage; and

a first valve provided in the first gas passage, wherein

the controller, when the output of the target material from the nozzle is to be stopped, closes the first valve and opens the pressure-decrease valve, to thereby decrease the pressure inside the tank, then closes the pressure-decrease valve, opens the first valve, and further decreases the pressure inside the tank by using the vacuum pump.

5. The target supply apparatus according to claim 4, further comprising:

a pressure-decrease tank connected to the exhaust port and having a large capacity as compared with a capacity of the tank;

a second gas passage connected at one end thereof to the pressure-decrease tank and connected at the other end thereof to the first gas passage between the first valve and the vacuum pump; and

a second valve provided in the second gas passage, wherein

the controller instructs the vacuum pump to evacuate the inside of the pressure-decrease tank with the second valve opened, and, when the output of the target material from the nozzle is to be stopped, closes the first valve and the second valve and opens the pressure-decrease valve, to thereby decrease the pressure inside the tank, then closes the pressure-decrease valve, opens the first valve, and further decreases the pressure inside the tank by using the vacuum pump.

6. The target supply apparatus according to claim 1, further comprising:

a pressure-decrease tank connected to the exhaust port and having a large capacity as compared with a capacity of the tank;

a first gas passage connected at one end thereof to the pressure-decrease tank;

a vacuum pump connected to the other end of the first gas passage; and

a first valve provided in the first gas passage, wherein

the controller instructs the vacuum pump to evacuate the inside of the pressure-decrease tank with the first valve opened, and, when the target material is not to be output from the nozzle, opens the pressure-decrease valve, to thereby decrease the pressure inside the tank.

7. The target supply apparatus according to claim 1, further comprising:

a high-precision pressure controller provided in the pressure-increase gas passage between the pressure regulator and the pressure-increase valve and capable of regulating the pressure with higher precision than the pressure regulator;

a first valve provided in the pressure-increase gas passage between the pressure regulator and the high-precision pressure controller;

a bypass gas passage for bypassing the first valve and the high-precision pressure controller; and

a second valve provided in the bypass gas passage, wherein

the controller, when the pressure inside the tank is to be increased, closes the first valve and opens the second valve, to thereby supply the gas pressure-regulated by the pressure regulator into the tank through the bypass gas passage, and then, opens the first valve and closes the second valve, to thereby supply the gas pressure-controlled by the high-precision pressure controller into the tank.