Method and apparatus for controlling a shape of a pattern over a substrate

Abstract

An apparatus and method process a substrate in a first session and a second session. In the first session, a hybrid gas application cycle is performed in a chamber that holds the substrate. A first gas is introduced for a first time period so components of the first gas adsorb onto the substrate. Subsequently, a second gas is introduced for a second time period so the second gas reacts with the components of the first gas to provide a protective layer on sidewalls of a pattern of the substrate, and the second gas etches a bottom portion of the pattern, a ratio of the first time period to the second time period being a use-ratio. Then, in a second session, the hybrid gas application cycle is repeated with a different use-ratio that corresponds with a vertical dimension of the pattern.

1 . An apparatus for processing a substrate in a chamber, the apparatus comprising:
 a non-transitory computer readable memory having instructions stored therein; and circuitry configured to execute the instructions to perform a method of processing the substrate in the chamber, the method comprising:   in a first session, performing a hybrid gas application cycle in the chamber that holds the substrate, the hybrid gas application cycle including:
 introducing a first gas as a precursor for a first time period in the chamber so that the precursor adsorbs onto the substrate, and 
 subsequently, introducing a second gas as a reaction gas for a second time period so that the reaction gas reacts with the precursor to provide a protective layer on a sidewall of a pattern of the substrate and, at the same time, the second gas etches a portion of the substrate at a bottom portion of the pattern so that an etch depth is increased and the protective layer is formed preferentially on the sidewall of the pattern, a ratio of the first time period to the second time period being a use-ratio; and 
   in a second session, repeating the hybrid gas application cycle with a different use-ratio that corresponds with a vertical dimension of the pattern.   
     
     
         2 . The apparatus of  claim 1 , wherein the circuitry is further configured to repeat the hybrid gas application cycle while maintaining the use-ratio, and at least one of the first gas or the second gas being a plasma. 
     
     
         3 . The apparatus of  claim 1 , wherein the pattern is a hole and the use-ratio for the first session is set to be less than the different use-ratio for the second session so as to form the hole with a tapered shape. 
     
     
         4 . The apparatus of  claim 1 , wherein the pattern is a hole and the use-ratio used in the first session is set to be greater than the different use-ratio for the second session so as to form the hole with wider dimension toward a bottom of the hole. 
     
     
         5 . The apparatus of  claim 1 , wherein the precursor is a silicon-containing gas, and the reaction gas is an oxygen radical gas. 
     
     
         6 . The apparatus of  claim 1 , wherein the reaction gas is an O-containing gas. 
     
     
         7 . The apparatus of  claim 1 , wherein the circuitry is further configured to perform a third session by repeating the hybrid gas application cycle with a greater use-ratio than the use-ratio of the first session and the different use-ratio of the second session. 
     
     
         8 . The apparatus of  claim 1 , wherein a number of hybrid gas application cycles performed in the first session is greater than that for the second session, and the use-ratio in the first session is greater than the different use-ratio in the second session. 
     
     
         9 . The apparatus of  claim 7 , wherein a number of hybrid gas application cycles performed in the second session is greater than that for the third session, and the different use-ratio in the second session is greater than that for the third session. 
     
     
         10 . The apparatus of  claim 1 , wherein the hybrid gas application cycle includes applying at least one of the first gas or the second gas as a plasma. 
     
     
         11 . The apparatus of  claim 1 , wherein the introducing the second gas comprises introducing the second gas after a predetermined time after the first time period has elapsed. 
     
     
         12 . The apparatus of  claim 1 , wherein the circuitry is further configured to, in the first session, perform an intermediate step between the introducing the first gas and the introducing the second gas. 
     
     
         13 . The apparatus of  claim 1 , wherein the chamber used in the step of introducing the first gas is a different chamber from that used in the step of introducing the second gas. 
     
     
         14 . An apparatus for processing a substrate in a chamber, the apparatus comprising:
 a non-transitory computer readable memory having instructions stored therein; and circuitry configured to execute the instructions to perform a method of processing the substrate, the method comprising:   in a first session, performing a hybrid gas application cycle in the chamber that holds the substrate, the hybrid gas application cycle including:
 introducing a first gas as a precursor for a first time period in the chamber so that the precursor adsorbs onto the substrate, 
 subsequently, introducing a second gas as a reaction gas so that the reaction gas reacts with the precursor to provide a protective layer on a sidewall of a pattern of the substrate, and 
 subsequently introducing another gas for a second time period so as to etch a portion of the substrate at a bottom portion of the pattern, a ratio of the first time period to the second time period being a use-ratio; and 
   in a second session, repeating the hybrid gas application cycle with a different use-ratio that corresponds with a vertical dimension of the pattern,   wherein the another gas is different from the second gas.   
     
     
         15 . The apparatus of  claim 14 , wherein the circuitry is further configured to repeat the hybrid gas application cycle while maintaining the use-ratio in the first session. 
     
     
         16 . The method of  claim 14 , wherein the hybrid gas application cycle includes applying at least one of the first gas or the second gas as a plasma. 
     
     
         17 . The method of  claim 14 , wherein the precursor is a silicon-containing gas, and the second gas is an oxygen radical gas. 
     
     
         18 . The method of  claim 14 , wherein the second gas is an  0 -containing gas. 
     
     
         19 . A substrate processing apparatus comprising:
 a chamber having a gas inlet and a gas outlet:   a substrate support disposed in the chamber:   a controller configured to cause:   (a) performing a hybrid gas application cycle with respect to a substrate placed on the substrate support, the substrate including a pattern having a sidewall and a bottom, the hybrid gas application cycle including:
 (a1) for a first time period, introducing a precursor into the chamber to form an adsorbed layer on the sidewall, and 
 (a2) for a second time period, introducing a reaction gas into the chamber to form a protective layer from the adsorbed layer on the sidewall and to etch the bottom; and 
   (b) repeating the hybrid gas application cycle with a variable ratio of the first time period to the second time, the variable ratio being changed according to a depth of the bottom in each hybrid gas application cycle.   
     
     
         20 . A substrate processing apparatus comprising:
 a chamber having a gas inlet and a gas outlet:   a substrate support disposed in the chamber:   a controller configured to cause:   (a) performing a hybrid gas application cycle with respect to a substrate placed on the substrate support, the substrate including a pattern having a sidewall and a bottom, the hybrid gas application cycle including:
 (a1) for a first time period, introducing a precursor into the chamber to form an adsorbed layer on the sidewall, 
 (a2) for a second time period, introducing a first reaction gas into the chamber to form a protective layer from the adsorbed layer on the sidewall, and
 (a3) for a third time period, introducing a second reaction gas into the chamber to etch the bottom, the second reaction gas being different from the first reaction gas; and 
 
   (b) repeating the hybrid gas application cycle with a variable ratio of the first time period to the third time period, the variable ratio being changed according to a depth of the bottom in each hybrid gas application cycle.