Patent ID: 6136634
Filing Date: 2000-10-24
Classification: H01L

Abstract:
A method for manufacture of a semiconductor device, comprising the steps of:providing a substrate;forming a polycrystalline silicon film on a major surface of said substrate, said polycrystalline silicon film having a thickness of 100 to 200 mn;defining first, second and third regions of said polycrystalline silicon film;ion implanting at least said first and second regions of said polycrystalline silicon film using BF.sub.2.sup.+ at a level for high resistance, said ion implanting of said first and second regions being performed at an implantation energy of 20 k to 40 keV and a dose of 1.times.10.sup.15 to 5.times.10.sup.14 cm.sup.-2 ;masking said third region and said first region;ion implanting said second region of said polycrystalline silicon film using BF.sub.2.sup.+ at a level for medium resistance, said ion implanting of said second region being performed at an implantation energy of 20 k to 40 keV and a dose of 1.times.10.sup.15 to 5.times.10.sup.15 cm.sup.-2 ;masking said second region and said first region;ion implanting said third region of said polycrystalline silicon film using Si.sup.+ and B.sup.+ at a level for low resistance, said ion implanting of said third region being performed at an Si.sup.+ implantation energy of 50 to 80 keV and a dose for the Si.sup.+ of 1.times.10.sup.15 to 5.times.10.sup.15 cm.sup.-2 and at a B.sup.30 implantation energy of 5 k to 15 keV and a dose for the B.sup.+ of 1.times.10.sup.15 to 3.times.10.sup.15 cm.sup.-2 ; andannealing for 30 to 300 minutes at a temperature of 550 to 650.degree. C. to provide a crystalline grain size of 20 to 70 nm for the first and second regions and a crystalline grain size of 90 to 500 nm for the third region; andforming resistors of said polycrystalline silicon film, including:forming a high resistance resistor of said first region of a resistance of 1 k to 4.5 k .OMEGA./.quadrature.,forming a medium resistance resistor of said second region of a resistance of 300 to 500 .OMEGA./.quadrature., andforming a low resistance resistor of said third region of a resistance of not more than 200 .OMEGA./.quadrature..