EUV Chamber Tin Oxidation Control via Low Oxygen Pressure
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Solution Overview
Problem
The oxidation of tin as a target material in EUV light generation apparatuses leads to tin oxide precipitation, causing nozzle clogging and affecting the focus of the pulse laser beam, which is difficult to suppress with existing technologies due to high oxygen partial pressures.
Innovation Solution
A chamber apparatus and method that control the oxygen partial pressure in the chamber to 4×10−5 Pa or lower, using a combination of an oxygen partial pressure gauge, a high-vacuum pump, and a dry pump in series, along with a filter to capture tin oxide particles, ensuring the tin ingot is melted and ejected under low oxygen conditions to prevent oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing vacuum technologies are used in EUV light generation apparatuses, then the apparatus can operate with standard vacuum systems, but tin oxidation occurs due to high oxygen partial pressures causing nozzle clogging
Solution Approach 1:
The patent applies inert atmosphere principle by introducing a nitrogen gas flow around the nozzle to create a protective atmosphere. The nitrogen gas supplies an inert environment that prevents oxygen from contacting the molten tin, thereby suppressing tin oxidation and preventing nozzle clogging while maintaining standard vacuum system operation
2Ease of operation
If oxygen partial pressure is not controlled, then the vacuum system is simpler to operate, but tin oxide precipitation occurs causing nozzle clogging and laser focus issues
Solution Approach 1:
The patent uses nitrogen gas as an intermediary substance between the vacuum environment and the molten tin. This intermediary gas layer acts as a barrier that prevents oxygen from reaching the tin without requiring complex vacuum control systems, thus maintaining ease of operation while ensuring manufacturing precision through prevented oxidation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively suppresses the oxidation of molten tin, reducing tin oxide precipitation and maintaining the integrity of the nozzle and ensuring precise EUV light generation by maintaining a low oxygen partial pressure during the tin ejection process.
Implementation Method 1
a variable temperature device configured to change a temperature of the tin in the tank part
Implementation Method 2
a pressure regulator configured to change a pressure in the tank part
Implementation Method 3
The controller may be configured to control A. the evacuation device to maintain an oxygen partial pressure in the chamber at 4×10−5 Pa or lower
Data Source
AI summary
In a chamber apparatus that includes a chamber and a target generation device configured to supply tin as a target material to a certain region in the chamber, oxidation of molten tin is prevented. A chamber apparatus includes: a chamber (1); a target generation device including a tank part (32) configured to store tin T, a variable temperature device (33, 38) configured to change a temperature of the tin T in the tank part (32), a pressure regulator (31) configured to change a pressure in the tank part (32), and a nozzle part (34) configured to eject liquefied tin T; a gas source (40) configured to supply gas containing hydrogen gas into the chamber (1); an evacuation device (46) configured to evacuate gaseous body in the chamber (1); and a controller (2) configured to control generation of a target, in which the controller (2) controls the evacuation device (46) to maintain an oxygen partial pressure in the chamber (1) at 4×10−5 Pa or lower.