Plasma etching method and plasma etching apparatus

Abstract

There are provided a plasma etching method and a plasma etching apparatus capable of independently controlling distributions of line widths and heights of lines in a surface of a wafer. The plasma etching method for performing a plasma etching on a substrate W by irradiating plasma containing charged particles and neutral particles to the substrate W includes controlling a distribution of reaction amounts between the substrate W and the neutral particles in a surface of the substrate W by adjusting a temperature distribution in the surface of the substrate W supported by a support 105 , and controlling a distribution of irradiation amounts of the charged particles in the surface of the substrate W by adjusting a gap between the substrate W supported by the support 105 and an electrode 120 provided so as to face the support 105.

1 . A plasma etching method for performing a plasma etching on a substrate by irradiating plasma containing charged particles and neutral particles to the substrate, the method comprising:
 controlling a distribution of reaction amounts between the substrate and the neutral particles in a surface of the substrate by adjusting a temperature distribution in the surface of the substrate supported by a support; and   controlling a distribution of irradiation amounts of the charged particles in the surface of the substrate by adjusting a gap between the substrate supported by the support and an electrode provided so as to face the support.   
     
     
         2 . The plasma etching method of  claim 1 , further comprising:
 an etching process for forming lines including a mask film by etching the mask film formed on the substrate by the irradiated plasma,   wherein, in the etching process, a distribution of line widths of the lines in the surface of the substrate is controlled by adjusting the distribution of reaction amounts, and a distribution of heights of the lines in the surface of the substrate is controlled by adjusting the distribution of irradiation amounts.   
     
     
         3 . The plasma etching method of  claim 2 , wherein the etching process includes:
 a second mask film etching process for forming the lines including a second mask film by irradiating first plasma containing first charged particles and first neutral particles to the substrate and etching the second mask film formed on the substrate via a first mask film by the irradiated first plasma; and   a first mask film etching process for forming the lines including the first mask film by irradiating second plasma containing second charged particles and second neutral particles to the substrate on which the lines including the second mask film are formed and etching the first mask film by the irradiated second plasma,   wherein temperature dependency of a reaction amount between the second mask film and the first neutral particles is lower than temperature dependency of a reaction amount between the first mask film and the second neutral particles.   
     
     
         4 . The plasma etching method of  claim 1 , wherein the distribution of reaction amounts in the surface of the substrate is controlled by adjusting the temperature distribution and a distribution of a supply amount or a composition ratio of a processing gas supplied to the substrate. 
     
     
         5 . The plasma etching method of  claim 4 , further comprising:
 an etching process for forming first lines including the mask film and spaced apart from each other at a first gap and second lines including the mask film and spaced apart from each other at a second gap greater than the first gap by etching the mask film formed on the substrate by the irradiated plasma,   wherein, in the etching process, a distribution of line widths of the first lines and the second lines in the surface of the substrate is controlled by adjusting the distribution of reaction amounts, and a distribution of heights of the first lines and the second lines in the surface of the substrate is controlled by adjusting the distribution of irradiation amounts, and   temperature dependency of a first reaction amount between the first lines and the neutral particles is lower than temperature dependency of a second reaction amount between the second lines and the neutral particles.   
     
     
         6 . The plasma etching method of  claim 5 , wherein the etching process includes:
 a second mask film etching process for forming the first lines and the second lines each including a second mask film by irradiating first plasma containing first charged particles and first neutral particles to the substrate and etching the second mask film formed on the substrate via a first mask film by the irradiated first plasma; and   a first mask film etching process for forming the first lines and the second lines each including the first mask film by irradiating second plasma containing second charged particles and second neutral particles to the substrate on which the first lines and the second lines each including the second mask film are formed and etching the first mask film by the irradiated second plasma,   wherein temperature dependency of a reaction amount between the second mask film and the first neutral particles is lower than temperature dependency of a reaction amount between the first mask film and the second neutral particles.   
     
     
         7 . The plasma etching method of  claim 3 , wherein the first mask film includes an inorganic film and the second mask film includes an organic film, and
 the first neutral particles include oxygen radicals and the second neutral particles include fluorine radicals.   
     
     
         8 . The plasma etching method of  claim 6 , wherein the first mask film includes an inorganic film and the second mask film includes an organic film, and
 the first neutral particles include oxygen radicals and the second neutral particles include fluorine radicals.   
     
     
         9 . A plasma etching apparatus configured to perform a plasma etching on a substrate by irradiating plasma containing charged particles and neutral particles to the substrate, the apparatus comprising:
 a support capable of supporting the substrate;   an electrode provided so as to face the support;   a temperature distribution adjusting unit capable of adjusting a temperature distribution in a surface of the substrate supported by the support;   a gap adjusting unit capable of adjusting a gap between the substrate supported by the support and the electrode; and   a controller capable of controlling a distribution of reaction amounts between the substrate and the neutral particles in the surface of the substrate by adjusting the temperature distribution by the temperature distribution adjusting unit and capable of controlling a distribution of irradiation amounts of the charged particles in the surface of the substrate by adjusting the gap by the gap adjusting unit.   
     
     
         10 . The plasma etching apparatus of  claim 9 , wherein lines including a mask film are formed by etching the mask film formed on the substrate by the irradiated plasma, and
 when the lines are formed, the controller controls a distribution of line widths of the lines in the surface of the substrate by adjusting the distribution of reaction amounts, and the controller controls a distribution of heights of the lines in the surface of the substrate by adjusting the distribution of irradiation amounts.   
     
     
         11 . The plasma etching apparatus of  claim 10 , wherein the lines including a second mask film are formed by irradiating first plasma containing first charged particles and first neutral particles to the substrate and etching the second mask film formed on the substrate via a first mask film by the irradiated first plasma; and
 the lines including the first mask film are formed by irradiating second plasma containing second charged particles and second neutral particles to the substrate on which the lines including the second mask film are formed and etching the first mask film by the irradiated second plasma,   wherein temperature dependency of a reaction amount between the second mask film and the first neutral particles is lower than temperature dependency of a reaction amount between the first mask film and the second neutral particles.   
     
     
         12 . The plasma etching apparatus of  claim 9 , further comprising:
 a supply amount distribution adjusting unit capable of adjusting a distribution of a supply amount or a composition ratio of a processing gas supplied to the substrate in the surface of the substrate,   wherein the controller controls the distribution of reaction amounts by adjusting the temperature distribution by the temperature distribution adjusting unit and by adjusting the distribution of the supply amount or composition ratio in the surface of the substrate by the supply amount distribution adjusting unit.   
     
     
         13 . The plasma etching apparatus of  claim 12 , wherein first lines spaced apart from each other at a first gap and including the mask film and second lines spaced apart from each other at a second gap greater than the first gap and including the mask film are formed by etching the mask film formed on the substrate by the irradiated plasma,
 when the first lines and the second lines are formed, the controller controls a distribution of line widths of the first lines and the second lines in the surface of the substrate by adjusting the distribution of reaction amounts, and the controller controls a distribution of heights of the first lines and the second lines in the surface of the substrate by adjusting the distribution of irradiation amounts, and   temperature dependency of a first reaction amount between the first lines and the neutral particles is lower than temperature dependency of a second reaction amount between the second lines and the neutral particles.   
     
     
         14 . The plasma etching apparatus of  claim 13 , wherein the first lines and the second lines each including a second mask film are formed by irradiating first plasma containing first charged particles and first neutral particles to the substrate and etching the second mask film formed on the substrate via a first mask film by the irradiated first plasma; and
 the first lines and the second lines each including the first mask film are formed by irradiating second plasma containing second charged particles and second neutral particles to the substrate on which the first lines and the second lines each including the second mask film are formed and etching the first mask film by the irradiated second plasma,   wherein temperature dependency of a reaction amount between the second mask film and the first neutral particles is lower than temperature dependency of a reaction amount between the first mask film and the second neutral particles.   
     
     
         15 . The plasma etching apparatus of  claim 11 , wherein the first mask film includes an inorganic film and the second mask film includes an organic film, and
 the first neutral particles include oxygen radicals and the second neutral particles include fluorine radicals.   
     
     
         16 . The plasma etching apparatus of  claim 14 , wherein the first mask film includes an inorganic film and the second mask film includes an organic film, and
 the first neutral particles include oxygen radicals and the second neutral particles include fluorine radicals.