Low pressure chemical vapor deposition boro‐hydro‐nitride films and their use in x‐ray masks

This paper describes the characterization of amorphous B–H–N films deposited by low pressure chemical vapor deposition, and their use in the fabrication of mask substrates for a step and repeat x‐ray lithography system utilizing a storage ring source. The chemical composition of the films was analyzed by ion beam techniques. Because the experimental results indicate that the chemical composition differs from stoichiometric boron nitride, it is proposed to call them ‘‘boro‐hydro‐nitride’’ (B–H–N) films. The stress and optical properties of the films were measured for various values of the deposition parameters. It is shown that these properties can be correlated to the hydrogen content of the films. Membranes ∼2 μm thick with a central area 6 cm in diameter are presently fabricated for x‐ray mask substrates.