Transitor having a germanium implant region located therein and a method of manufacture therefor

Abstract

The present invention provides a transistor 100 having a germanium implant region 170 located therein, a method of manufacture therefor, and an integrated circuit including the aforementioned transistor. The transistor 100 , in one embodiment, includes a polysilicon gate electrode 140 located over a semiconductor substrate 110 , wherein a sidewall of the polysilicon gate electrode 140 has a germanium implanted region 170 located therein. The transistor 100 further includes source/drain regions 160 located within the semiconductor substrate 110 proximate the polysilicon gate electrode 140.

1 . A method comprising:
 forming a polysilicon gate electrode having a first sidewall and an opposite second sidewall over a substrate;   implanting a dopant into the substrate to form a first region and a second region having a channel region therebetween, wherein the polysilicon gate electrode is located substantially between the first and second regions over at least a portion of the channel region; and   implanting germanium at an angle that is greater than about 30° from an axis that is substantially perpendicular to the substrate into the first and second sidewalls to form a germanium implanted region.   
   
   
       2 . The method of  claim 1 , wherein the concentration of germanium in the germanium implanted region is between about 2*10 21  atoms/cm 3  and about 8*10 21  atoms/cm 3 . 
   
   
       3 . The method of  claim 1 , wherein the dose used to form the germanium implant region is between about 4*10 15  atoms/cm 2  and about 2*10 16  atoms/cm 2  having a peak concentration of no less than about 2*10 21  atoms/cm 3 . 
   
   
       4 . The method of  claim 1 , wherein the implant energy for the germanium is between about 3 keV and about 10 keV. 
   
   
       5 . The method of  claim 1 , wherein the step of implanting the germanium further comprises implanting the germanium into the first and second regions. 
   
   
       6 . The method of  claim 1 , wherein the method further comprises forming a blanket oxide layer over the first and second regions prior to the step of implanting the germanium. 
   
   
       7 . The method of  claim 1 , wherein the dopant is a P-type dopant. 
   
   
       8 . The method of  claim 1 , wherein the angle is between about 40° and about 60°. 
   
   
       9 . A method comprising:
 forming a well region of a first conduction type in a substrate;   forming a dielectric over at least a portion of a the well region;   forming a polysilicon layer over the dielectric layer to form a gate electrode;   implanting a first dopant into the well to form a first region and a second region of a second conduction type having a channel region of the first conduction type therebetween, wherein the gate electrode is located substantially between the first and second regions over at least a portion of the channel region;   forming a first and an opposite second sidewall on each side of the polysilicon gate electrode;   implanting a second dopant into the well region to form a halo implant of the first conduction type substantially below each of the first and second regions; and   implanting germanium at an angle that is greater than about 30° from an axis that is substantially perpendicular to the substrate into the first and second sidewalls to form a germanium implanted region.   
   
   
       10 . The method of  claim 9 , wherein the concentration of germanium in the germanium implanted region is between about 2*10 21  atoms/cm 3  and about 8*10 21  atoms/cm 3 . 
   
   
       11 . The method of  claim 9 , wherein the dose used to form the germanium implant region is between about 4*10 15  atoms/cm 2  and about 2*10 16  atoms/cm 2  having a peak concentration of no less than about 2*10 21  atoms/cm 3 . 
   
   
       12 . The method of  claim 9 , wherein the implant energy for the germanium is between about 3 keV and about 10 keV. 
   
   
       13 . The method of  claim 9 , wherein the step of implanting the germanium further comprises implanting the germanium into the first and second regions. 
   
   
       14 . The method of  claim 9 , wherein the method further comprises forming a blanket oxide layer over the first and second regions prior to the step of implanting the germanium. 
   
   
       15 . The method of  claim 9 , wherein the first dopant is a P-type dopant and the second dopant is an N-type dopant. 
   
   
       16 . The method of  claim 9 , wherein the angle is between about 40° and about 60°. 
   
   
       17 . A method comprising:
 forming an N-type well region in a P-type substrate;   forming a gate oxide layer over at least a portion of the N-type well region;   forming a polysilicon layer over the gate oxide layer to form a gate electrode;   implanting a P-type dopant into the well region to form a first P-type source/drain region and a second P-type second source/drain region having an N-type channel region formed therebetween, wherein the gate electrode is located substantially between the first and second P-type source/drain regions over at least a portion of the N-type channel region;   forming a first and an opposite second sidewall spacer on each side of the gate electrode, wherein each of the first and second sidewall spacers extends over at least a portion of one of the first and second source/drain regions, and wherein the first and second side walls are formed by chemical vapor deposition and anisotropic etching;   implanting an N-type dopant into the well to form N-type halo implants substantially below each of the first and second source/drain regions; and   implanting germanium at an angle that is greater than about 30° from an axis that is substantially perpendicular to the substrate into the first and second sidewalls to form a germanium implanted region.   
   
   
       18 . The method of  claim 17 , wherein the method further comprises forming a blanket oxide layer over the first and second regions prior to the step of implanting the germanium. 
   
   
       19 . The method of  claim 17 , wherein the angle is between about 40° and about 60°. 
   
   
       20 . The method of  claim 19 , wherein the N-type dopant is arsenic or phosphorous.