Hydrogen Damage Test Technology Study for Materials under Low-pressure Hydrogen Condition

In order to evaluate the hydrogen embrittlement of materials in extreme ultraviolet lithography (EUVL) vacuum system, a novel test method was proposed to speculate the hydrogen sensibility under low-pressure hydrogen condition and its time-evolution. Firstly, the material's hydrogen concentration and variation trend could be obtained using a low-pressure gaseous hydrogen charging set and a hydrogen content analyzer. In the meantime, the fracture threshold stress and hydrogen embrittlement exponent of materials with various hydrogen concentrations could be acquired using a constant load set under electrochemical hydrogen charging condition. Combining the above two, the fracture threshold stress and hydrogen embrittlement exponent in different periods of time for materials under low-pressure gaseous hydrogen condition could be calculated theoretically at last. With the purpose of verifying the correctness of the new principle and having a wise judgement, 304SS and 65Mn were chosen as representative materials and their hydrogen susceptibility was measured using this method. The results reveal that the longer the time for the material in the 10Pa hydrogen environment, the lower the possibility for the material to fail due to hydrogen embrittlement. Under a certain concentration condition, 65Mn showed a higher hydrogen susceptibility than 304SS, which is in accord with the literature. It is indicated that the test method and results have practical value in the EUVL material selection.