Protective offset sputtering

Abstract

Sputtering in a physical vapor deposition (PVD) chamber may, in one embodiment, utilize a target laterally offset from and tilted with respect to the substrate. In another aspect, target power may be reduced to enhance film protection. In yet another aspect, magnetron magnets may be relatively strong and well balanced to enhance film protection. In another aspect, a shutter may be provided to protect the substrate in start up conditions. Other embodiments are described and claimed.

1 - 63 . (canceled) 
     
     
         64 . A physical vapor deposition chamber for depositing target material on a surface of a semiconductor wafer substrate having a center, comprising:
 a chamber body;   a sputterable target having sputtering surface which has a center and a central axis;   a magnetron positioned adjacent the target wherein the magnetron has poles which produce a magnetic field having a total field strength of at least 50 gauss at the surface of poles;   a rotatable substrate pedestal disposed in the chamber body and having a pedestal surface which defines a plane and is adapted to support a semiconductor wafer substrate in a predetermined position relative to said target wherein said target sputtering surface is laterally offset with respect to said substrate center within a range of 300 to 400 mm; and a computer-based controller programmed to control sputtering of the target to deposit target material on said semiconductor wafer substrate to form a layer in a gate of a transistor, said gate layer having a thickness less than 100 angstroms and to inhibit plasma damage to underlying material of said gate while depositing said gate layer.   
     
     
         65 . The chamber of  claim 64  wherein the magnetron has a center pole and at least one outer pole wherein the magnetic strength of the center pole is at least half that of the outer poles. 
     
     
         66 . The chamber of  claim 64  wherein said computer-based controller is further programmed to control the pressure within said chamber within a range of 1 to 7 milliTorr. 
     
     
         67 . The chamber of  claim 64  further comprising a working gas within said chamber body selected from a group consisting of neon, argon, krypton, xenon, and a mixture of two or more gases from selected from the group consisting of neon, argon, krypton, xenon. 
     
     
         68 . The chamber of  claim 64  further comprising one or more reactive gases within said chamber body selected from a group consisting of N 2 , O 2 , CH 4 , and NH 3 . 
     
     
         69 . The chamber of  claim 64  further comprising a shutter disk adapted to shield the substrate from plasma spikes in an initial plasma ignition and stabilization stage and further adapted to be moved to expose the whole substrate to chamber plasma for film deposition. 
     
     
         70 . The chamber of  claim 64  wherein the computer-based controller is further programmed to control the power of a signal biasing said target within a power range of 50 to 6000 watts. 
     
     
         71 . The chamber of  claim 64  wherein said target sputtering surface has a central axis which is substantially parallel with respect to said pedestal surface plane. 
     
     
         72 . The chamber of  claim 64  wherein said target sputtering surface has a substantial lateral offset with respect to said substrate center and has a central axis which is substantially orthogonal with respect to said pedestal surface plane. 
     
     
         73 . The chamber of  claim 64  wherein the target central axis is disposed at an angle between about 40 to about 75 degrees with respect to the pedestal surface plane. 
     
     
         74 . The chamber of  claim 64  wherein the target sputtering surface is disposed at an angle between about 15 to about 50 degrees with respect to the pedestal surface plane. 
     
     
         75 . The chamber of  claim 64  wherein said target sputtering surface center is vertically offset with respect to said substrate center within a range of 300 to 400 mm. 
     
     
         76 . The chamber of  claim 64  further comprising a temperature controller adapted to control the substrate temperature in a range of −20 degrees C. to 450 degrees C. 
     
     
         77 . A physical vapor deposition chamber for depositing target material on a surface of a semiconductor wafer substrate having a center, comprising:
 a chamber body;   a sputterable target having sputtering surface which has a center and a central axis;   a magnetron positioned adjacent the target wherein the magnetron has poles which produce a magnetic field having a total field strength of at least 50 gauss at the surface of poles;   a rotatable substrate pedestal disposed in the chamber body and having a pedestal surface which defines a plane and is adapted to support a semiconductor wafer substrate in a predetermined position relative to said target wherein said target sputtering surface is laterally offset with respect to said substrate center within a range of 300 to 400 mm;   and a computer-based controller programmed to control a physical vapor deposition process within the chamber body, said process comprising:   forming a gate of a transistor on a semiconductor wafer substrate, said forming including:   rotating the magnetron adjacent the target;   rotating said semiconductor wafer substrate on the pedestal support surface in the chamber body;   sputtering a surface of the target to deposit target material on a surface of said substrate in a layer of said gate wherein said gate layer has a thickness less than 100 angstroms; and   inhibiting plasma damage to underlying material of said gate while depositing said layer, said inhibiting including sputtering the target sputtering surface laterally offset with respect to the center of the substrate surface within a range of 300 to 400 mm.   
     
     
         78 . The chamber of  claim 77  wherein the magnetron has a center pole and at least one outer pole wherein said inhibiting includes the magnetic strength of the center pole being at least half that of the outer poles. 
     
     
         79 . The chamber of  claim 77  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to control the pressure within said chamber within a range of 1 to 7 milliTorr. 
     
     
         80 . The chamber of  claim 77  further comprising a working gas within said chamber wherein said working gas is selected from a group consisting of neon, argon, krypton, xenon, and a mixture of two or more gases from selected from the group consisting of neon, argon, krypton, xenon. 
     
     
         81 . The chamber of  claim 77  further comprising a reactive gas within said chamber wherein said reactive gas is selected from a group consisting of N 2 , O 2 , CH 4 , and NH 3 . 
     
     
         82 . The chamber of  claim 77  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to control the power of a signal biasing said target within a power range of 50 to 6000 watts. 
     
     
         83 . The chamber of  claim 77  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to sputter the target sputtering surface disposed at an angle between about 0 to about 90 degrees with respect to the pedestal surface plane. 
     
     
         84 . The chamber of  claim 77  wherein said target sputtering surface has a central axis which is substantially parallel with respect to said pedestal surface plane. 
     
     
         85 . The chamber of  claim 77  wherein said target sputtering surface has a central axis which is substantially orthogonal with respect to said pedestal surface plane. 
     
     
         86 . The chamber of  claim 77  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to sputter the target sputtering surface having the target central axis disposed at an angle between about 40 to about 75 degrees with respect to the pedestal surface plane. 
     
     
         87 . The chamber of  claim 83  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to sputter the target sputtering surface disposed at an angle between about 15 to about 50 degrees with respect to the pedestal surface plane. 
     
     
         88 . The chamber of  claim 77  wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to sputter said target sputtering surface center vertically offset with respect to said substrate center within a range of 300 to 400 mm. 
     
     
         89 . The chamber of  claim 77  wherein the magnetron has poles and wherein said inhibiting includes said poles producing a magnetic field having a total field strength of at least 50 gauss at the surface of poles. 
     
     
         90 . The chamber of  claim 77  wherein said computer-based controller programmed to control said gate forming of said process, is further programmed to control the substrate temperature of said process in a range of −20 degrees C. to 450 degrees C. 
     
     
         91 . The chamber of  claim 77  wherein said gate has a layer of insulative material and wherein said computer-based controller programmed to control said sputtering of said gate forming of said process further includes said computer-based controller programmed to control sputtering the surface of the target to deposit a layer of conductive material of said gate wherein said gate conductive layer has a thickness less than 50 nm directly on the layer of insulative material of said gate; and
 wherein said computer-based controller programmed to control said inhibiting of said gate forming of said process further includes said computer-based controller programmed to inhibit plasma damage to said layer of gate insulative material while depositing said gate conductive layer, said inhibiting including laterally offsetting the target sputtering surface with respect to the center of the substrate within a range of 300 to 400 mm.