CU FILMS BY PARTIALLY-IONIZED BEAM DEPOSITION FOR ULTRA LARGE-SCALE INTEGRATION METALLIZATION

Highly (111) oriented Cu films with a thickness around 1800 Angstrom w ere prepared on Si(100) at room temperature by partially ionized beam deposition (PIBD) at pressure of 8 X 10(-7)-1 X 10(-6) Torr, Effects o f acceleration voltage (V-a) between 0 and 4 kV on such properties as crystallinity, surface roughness, resistivity, etc. of the films have been investigated, The Cu films deposited by PIBD had only (111) and ( 200) planes, and the relative intensity ratio, I(111)/I(200) of the Cu films increased from 6.8 at V-a = 0 kV to 37 at V-a = 4 kV. There was no indication of impurities in the system front Auger electron spectr oscopy (AES) analyses. A large increase in grain size of the films occ urred with V-a up to V-a = 1 kV, but little increase occurred with V-a > 1 kV. Surface roughness of the Cu films decreased with V-a, and res istivity showed the same trends as that of the surface roughness. In t he Cu films by PIBD, it is considered that changes of resistivity are mainly due to a surface scattering rather than a grain boundary scatte ring. The via holes, dimensions of which are 0.5 mu m in diameter and 1.5 mu m in depth, in the Cu films made at V-a = 4 kV were completely filled without voids. Interface adhesion of the Cu film on Si(100) dep osited at V-a, = 3 kV was five times greater than that of Cu film depo sited at V-a = 0 kV, as determined by a scratch test.