Method for reproducible manufacture of metallic layers

Claim 1

A method for reproducible manufacture of metallic layers for semiconductor and thin film technology with the aid of an operable material deposition system including an enclosed vacuum chamber, a substrate positioned in said chamber, heat-exchange means for controlling the temperature of said substrate, at least one metallic material source positioned in said chamber facing said substrate, energy means for supplying energy to said material source, a doping gas source connected via a controllable valve with said chamber, measuring means for determining thickness of a layer deposited on said substrate, measuring means for determining resistance of a layer deposited on said substrate and control means interconnected with and selectively controlling said heat-exchange means, said energy means and said doping gas source relative to a signal derived from said measuring means, comprising the steps of: (a) continuously depositing and building a metallic layer on said substrate; (b) cyclically and independently measuring the thickness, d, and the electrical resistance of said metallic layer and generating signals corresponding to such measured values; (c) forming index values for, ρ∞, l∞, p, h and cyclically determining the specific electrical resistance, ρ, as a function of layer thickness, d, in accordance with the expression: ##EQU3## with d(x)=d+h sin 2π/s × and ##EQU4## wherein ρ∞ is the specific electrical resistance of an "infinite" thick layer with an internal structure identical to the said metallic layer; l∞ is the mean free path length of an "infinite" thick layer with an internal structure identical to the said metallic layer; p is a reflection parameter equal to the proportion of electrons reflected without resistance loss at the surface of said layer; h is the mean roughness amplitude of the surface of said layer; t is an integration variable and s is the wavelength of periodic thickness fluctuations of said layer; (d) cyclically determining the actual values of ρ∞, l∞, p and h relative to said measured values and comparing the same to said respective index values so as to derive respective control parameters; and (e) selectively applying said control parameters to said control means for regulating material deposition rate, substrate temperature, layer composition and doping gas pressure.

Claim 2

A method for reproducible manufacture of metallic layers for semiconductor and thin film technology with the aid of an operable material deposition system including an enclosed vacuum chamber, a substrate positioned in said chamber, heat-exchange means for controlling the temperature of said substrate, at least one metallic material source positioned in said chamber facing said substrate, energy means for supplying energy to said material source, a doping gas source connected via a controllable valve with said chamber, measuring means for determining thickness of a layer deposited on said substrate, measuring means for determining resistance of a layer deposited on said substrate and control means interconnected with and selectively controlling said heat-exchange means, said energy means and said doping gas source relative to a signal derived from said measuring means, comprising the steps of: (a) continuously depositing and building a metallic layer on said substrate; (b) cyclically and independently measuring the thickness, d, and the electrical resistance of said metallic layer and generating signals corresponding to such measured values; (c) forming index values for, ρ∞, l∞, p, h and cyclically determining the specific electrical resistance, ρ, as a function of layer thickness, d, in accordance with the expression: ##EQU3## with d(x)=d+h sin 2π/s × and ##EQU4## wherein ρ∞ is the specific electrical resistance of an "infinite" thick layer with an internal structure identical to the said metallic layer; l∞ is the mean free path length of an "infinite" thick layer with an internal structure identical to the said metallic layer; p is a reflection parameter equal to the proportion of electrons reflected without resistance loss at the surface of said layer; h is the mean roughness amplitude of the surface of said layer; t is an integration variable and s is the wavelength of periodic thickness fluctuations of said layer; (d) cyclically determining the actual values of ρ∞, l∞, p and h relative to said measured values and comparing the same to said respective index values so as to derive respective control parameters; and (e) selectively applying said control parameters to said control means for regulating material deposition rate, substrate temperature, layer composition and doping gas pressure.