METHOD FOR PRODUCTION OF JUNCTIONS IN SEMICONDUCTOR DEVICES Russian patent published in 1996 - IPC

FIELD: microelectronics. SUBSTANCE: method involves deposition of metal alloy on silicon substrate with dielectric layer. Deposition is done by thermal evaporation in vacuum. Alloy contains three components from three groups (by mass): Mn, Mg 0.5-3 %; Ni, Ti, Cr 1-5 %; Al, Au, Pt, Pd, Cu is the rest. Evaporation temperature is changed in three stages. During first and second stage temperature of evaporator is decreased as hyperbolic function when corresponding component of alloy is evaporated. Then, temperature is increased up to temperature for evaporation of next component when previous component is exhausted. During third stage temperature is kept constant until all alloy is evaporated. Evaporation is done in cylinder crucible evaporator, which height-to-diameter ratio is greater than three. Crucible evaporator generates constant and uniform gradient of temperature in perpendicular to its vertical axis. Gradient F conforms to equation

where ν is kinematic viscosity of melt, K_m and K_c are values of heat conductance of melt and crucible, correspondingly; h_o is initial height of melt level in evaporator before evaporation; g is acceleration of gravity; β is temperature rate for change of melt volume; R is radius of base of crucible; D and t_v are coefficient of molecular diffusion and time for total evaporation most volatile component from melt; Gr_m is minimal critical Grashof number, which determines boundary for stability of stationary free convection in melt. EFFECT: increased functional capabilities. 3 dwg