Process for manufacturing a semiconductor substrate comprising laminated copper, silicon oxide and silicon nitride layers

A method of manufacturing a semiconductor device comprising a rolled metal substrate made of metal selected from the group consisting of copper and a copper alloy composed of copper as a matrix and at least one other element in an amount of 50 wt % or less, wherein the surface of said metal substrate has a roughness of Rmax.gtoreq.0.1 micron, an insulating film provided on a portion of the top surface of said metal substrate leaving a portion of the metal substrate exposed, which insulating film has a thickness of from 3 microns to 10 microns inclusive, wherein said insulating film is made by the plasma CVD method, a semiconductor element mounted on one of said insulating film and an exposed surface of said metal substrate, and at least one of signal film wirings and power film wirings, and passive elements selected from the group consisting of a film resistor and a film capacitor, mounted on said insulating film, said insulating film selected from the group consisting of (1) a single-layer film made of a mixture of silicon oxide and silicon nitride and (2) a multi-layered film having two or more layers laminated one on another and comprising (a) a silicon oxide layer and at least one of (b) a layer made of a mixture of silicon oxide and silicon nitride and (c) a silicon nitride layer, said insulating film having a nitrogen to silicon content of 0.3 to 0.8 and wherein the insulating film has an intrinsic stress measured as a compressive or tensile stress of not more than 8.times.10.sup.9 (dyn/cm.sup.2), said method comprising the steps of removing an oxide layer on the surface of said metal substrate by electrochemical treatment, and forming said insulating film on the surface of said metal substrate by the plasma CVD technique using as material gases a silicon source gas selected from Si.sub.n H.sub.2n2 (n=1, 2, 3, or 4) and Si(C.sub.2 H.sub.5 O).sub.4, a nitrogen source gas selected from NH.sub.3 and N.sub.2, and an oxygen source gas containing one or more selected from N.sub.2 O, NO, NO.sub.2, O.sub.2 and O.sub.3 under the conditions of:

• metal substrate temperature:
• 200.degree.-350.degree., gas pressure at plasma discharge for pretreatment:
• 0.5 to 30 Torr, applied high-frequency wave output:
• 0.5-10 w/cm.sup.2, discharge time:
• five minutes or longer, gas pressure when forming film 0.1-5 Torr, gas flow ratio:
• Fs/(Fn+Fo).ltoreq.2 {wherein Fs is an Si source gas flow, Fn is an N source gas flow, and Fe is an 0 source gas flow}, high-frequency wave output density:
• 0.1-2.0 w/cm.sup.2, distance between the substrate and electrodes:
• 20-40 mm, and substrate temperature:
• 200.degree.-350.degree. C.

A method of manufacturing a semiconductor device comprising a rolled metal substrate made of metal selected from the group consisting of copper and a copper alloy composed of copper as a matrix and at least one other element in an amount of 50 wt % or less, wherein the surface of said metal substrate has a roughness of Rmax.gtoreq.0.1 micron, an insulating film provided on a portion of the top surface of said metal substrate leaving a portion of the metal substrate exposed, which insulating film has a thickness of from 3 microns to 10 microns inclusive, wherein said insulating film is made by the plasma CVD method, a semiconductor element mounted on one of said insulating film and an exposed surface of said metal substrate, and at least one of signal film wirings and power film wirings, and passive elements selected from the group consisting of a film resistor and a film capacitor, mounted on said insulating film, said insulating film selected from the group consisting of (1) a single-layer film made of a mixture of silicon oxide and silicon nitride and (2) a multi-layered film having two or more layers laminated one on another and comprising (a) a silicon oxide layer and at least one of (b) a layer made of a mixture of silicon oxide and silicon nitride and (c) a silicon nitride layer, said insulating film having a nitrogen to silicon content of 0.3 to 0.8 and wherein the insulating film has an intrinsic stress measured as a compressive or tensile stress of not more than 8.times.10.sup.9 (dyn/cm.sup.2), said method comprising the steps of removing an oxide layer on the surface of said metal substrate by electro-chemical treatment, and forming said insulating film on the surface of said metal substrate by the plasma CVD technique using as material gases a silicon source gas selected from Si.sub.n H.sub.2n+2 (n=1, 2, 3 or 4) and Si(C.sub.2 H.sub.5 O).sub.4, a nitrogen source gas selected from NH.sub.3 and N.sub.2, and an oxygen source gas containing one or more selected from N.sub.2 O, NO, NO.sub.2 O.sub.2 and O.sub.3 under the conditions of:

• metal substrate temperature:
• 350.degree. C. or less, gas pressure at plasma discharge for pretreatment:
• 0.1 to 30 Torr, applied high-frequency wave output:
• 0.1-10 w/cm.sup.2, discharge time:
• one minute or longer, gas pressure when forming film:
• 0.1-5 Torr, gas flow ratio:
• 0.1.ltoreq.2 {wherein Fs is an Si source gas flows, Fn is an N source gas flow, and Fe is an O source gas flow}, high-frequency wave output density:
• 0.1-2.0 w/cm.sup.2, distance between the substrate and electrodes:
• 10-40 mm, and substrate temperature:
• 350.degree. C. or less.