Method of removing photoresist

Abstract

A method includes forming a photoresist pattern over a certain portion of a material layer to expose an ion implantation region, implanting impurities in the ion implantation region of the material layer using the photoresist pattern as an ion implantation barrier, and removing the photoresist pattern using plasma of a gas mixture including a hydrocarbon-based gas.

1 . A method, comprising:
 forming a photoresist pattern over a certain portion of a material layer to expose an ion implantation region;   implanting impurities in the ion implantation region of the material layer using the photoresist pattern as an ion implantation barrier; and   removing the photoresist pattern using plasma of a gas mixture including a hydrocarbon-based gas.   
   
   
       2 . The method of  claim 1 , wherein removing the photoresist pattern comprises removing the photoresist pattern at different temperatures and in a predetermined removal sequence. 
   
   
       3 . The method of  claim 2 , wherein removing the photoresist pattern comprises:
 performing a first step at a first temperature using a plasma of a hydrocarbon-based gas and oxygen;   performing a second step at a second temperature, that is higher than the first temperature, using the plasma of the hydrocarbon-based gas and oxygen; and   performing a third step using a plasma of a hydrocarbon-based gas alone.   
   
   
       4 . The method of  claim 3 , wherein the first temperature ranges from approximately 100° C. to approximately 160° C. and the second temperature ranges from approximately 200° C. to approximately 250° C. 
   
   
       5 . The method of  claim 3 , wherein the hydrocarbon-based gas used in the first step to the third step comprises one of tetrafluoromethane (CH 4 ), ethylene (C 2 H 4 ), and a combination thereof. 
   
   
       6 . The method of  claim 3 , wherein a ratio of the hydrocarbon-based gas to the oxygen ranges approximately 4-10:1 in the first and the second steps. 
   
   
       7 . The method of  claim 3 , wherein microwave and radio frequency (RF) bias are simultaneously used to generate the plasma in the first step to the third step. 
   
   
       8 . The method of  claim 3 , wherein the plasma of the hydrocarbon-based gas and oxygen used in the first and the second steps further comprises nitrogen. 
   
   
       9 . The method of  claim 8 , further comprising, after implanting the impurities, performing a rinse treatment on the material layer using a solution including deionized water. 
   
   
       10 . The method of  claim 9 , wherein performing the rinse treatment comprises using a mixed solution including deionized water and ozone. 
   
   
       11 . The method of  claim 10 , wherein a temperature of the mixed solution including deionized water and ozone ranges from approximately 25° C. to approximately 80° C. 
   
   
       12 . The method of  claim 11 , wherein a concentration level of the ozone included in the mixed solution ranges from approximately 1 ppm to approximately 1,000 ppm. 
   
   
       13 . The method of  claim 1 , wherein the material layer comprises a polysilicon layer. 
   
   
       14 . The method of  claim 13 , wherein the impurities comprise one selected from a group consisting of arsenic (A), phosphorus (P), boron (B), and a combination thereof. 
   
   
       15 . A method, comprising:
 forming a photoresist pattern over a certain portions of a material layer to expose an ion implantation region;   implanting impurities in the ion implantation region of the material layer using the photoresist pattern as an ion implantation barrier; and   removing the photoresist pattern using plasma of a gas mixture including diimide (N 2 H 2 ).   
   
   
       16 . The method of  claim 15 , wherein removing the photoresist pattern comprises:
 performing a first step at a first temperature using plasma of N 2 H 2  and oxygen (O 2 );   performing a second step at a second temperature, that is higher than the first temperature, using the plasma of the N 2 H 2  and O 2 ; and   performing a third step using plasma of N 2 H 2 .   
   
   
       17 . The method of  claim 16 , wherein the first temperature ranges from approximately 100° C. to approximately 160° C. in the first step and the second temperature ranges from approximately 200° C. to approximately 250° C. in the second step. 
   
   
       18 . The method of  claim 16 , wherein the N 2 H 2  gas comprises approximately 4% of H 2  and approximately 96% of N 2  in the first step to the third step. 
   
   
       19 . The method of  claim 16 , wherein a ratio of the N 2 H 2  to the O 2  ranges approximately 4-6:1 in the first and the second steps. 
   
   
       20 . The method of  claim 16 , wherein microwave and radio frequency (RF) bias are simultaneously used to generate the plasma in the first step to the third step. 
   
   
       21 . The method of  claim 20 , further comprising, after implanting the impurities, performing a rinse treatment on the material layer using a solution including deionized water. 
   
   
       22 . The method of  claim 21 , wherein performing the rinse treatment comprises using a mixed solution including deionized water and ozone. 
   
   
       23 . The method of  claim 22 , wherein a temperature of the mixed solution including deionized water and ozone ranges from approximately 25° C. to approximately 80° C. 
   
   
       24 . The method of  claim 23 , wherein a concentration level of the ozone included in the mixed solution ranges from approximately 1 ppm to approximately 500 ppm. 
   
   
       25 . The method of  claim 15 , wherein the material layer comprises a polysilicon layer. 
   
   
       26 . The method of  claim 25 , wherein the impurities comprise one selected from a group consisting of arsenic (A), phosphorus (P), boron (B), and a combination thereof. 
   
   
       27 . The method of  claim 26 , wherein implanting the impurities comprises performing one of a beam line ion implantation and a plasma doping. 
   
   
       28 . A method, comprising:
 forming a first photoresist pattern over a polysilicon layer, the first photoresist pattern exposing a first portion of the polysilicon layer;   implanting first impurities into the first portion of the polysilicon layer using the first photoresist pattern as an ion implantation barrier;   removing the first photoresist pattern using plasma of a gas mixture including diimide (N 2 H 2 );   forming a second photoresist pattern over the polysilicon layer, the second photoresist pattern exposing a second portion of the polysilicon layer other than the first portion;   implanting second impurities into the second portion of the polysilicon layer using the second photoresist pattern as an ion implantation barrier; and   removing the second photoresist pattern using plasma of a gas mixture including N 2 H 2 .   
   
   
       29 . The method of  claim 28 , wherein each of removing the first photoresist pattern and removing the second photoresist pattern comprises:
 performing a first step at a first temperature using plasma of a gas including N 2 H 2  and oxygen (O 2 );   performing a second step at a second temperature, that is higher than the first temperature, using plasma of a gas including N 2 H 2  and O 2 ; and   performing a third step using plasma of N 2 H 2  alone.   
   
   
       30 . The method of  claim 29 , wherein the first temperature ranges from approximately 100° C. to approximately 160° C. in the first step and the second temperature ranges from approximately 200° C. to approximately 250° C. in the second step. 
   
   
       31 . The method of  claim 29 , wherein the N 2 H 2  gas comprises approximately 4% of H 2  and approximately 96% of N 2  in the first step to the third step. 
   
   
       32 . The method of  claim 29 , wherein a ratio of the N 2 H 2  to the O 2  ranges approximately 4-6:1 in the first and the second steps. 
   
   
       33 . The method of  claim 29 , wherein microwave and radio frequency (RF) bias are simultaneously used to generate the plasma in the first step to the third step. 
   
   
       34 . The method of  claim 28 , further comprising, after each of implanting the first impurities and implanting the second impurities, performing a rinse treatment on the polysilicon layer using a solution including deionized water. 
   
   
       35 . The method of  claim 34 , wherein performing the rinse treatment comprises using a mixed solution including deionized water and ozone. 
   
   
       36 . The method of  claim 35 , wherein a temperature of the mixed solution including deionized water and ozone ranges from approximately 25° C. to approximately 80° C. 
   
   
       37 . The method of  claim 36 , wherein a concentration level of the ozone included in the mixed solution ranges from approximately 1 ppm to approximately 500 ppm. 
   
   
       38 . The method of  claim 28 , wherein the first impurities comprise N-type impurities and the second impurities comprise P-type impurities. 
   
   
       39 . The method of  claim 28 , wherein the first impurities comprise P-type impurities and the second impurities comprise N-type impurities. 
   
   
       40 . The method of  claim 38 , wherein implanting the first and the second impurities comprises performing one of a beam line ion implantation and a plasma doping.