Dry etching Method

In a dry etching method comprising the steps of:

• introducing, into a vacuum chamber provided at a lower portion thereof with a sample stand, a raw-material gas mixture containing (i) an etching gas for etching a sample to be etched which is placed on said sample stand and in the surface of which a resist pattern is formed, and (ii) a lateral wall protecting gas for generating lateral wall protecting radicals for protecting the lateral walls of line patterns formed when said sample is etched, whereby ions composed of said gas mixture are generated;
• and
• applying a high-frequency electric power to said sample stand to form a self DC bias, thereby to induce said ions to said sample stand, whereby said sample is etched:
• said dry etching method comprising a parameter control step arranged such that,
• when the line width of a first line pattern, which is one of line patterns located at the inner side of a line pattern group comprising a plurality of line patterns adjacent to one another formed in a sample, is smaller than the line width of a second line pattern, which is one of outer line patterns located at the outermost side of said line pattern group or one of line patterns located as isolated from said line pattern group, and when the line width of each of said first and second line patterns is smaller than the line width of said resist pattern,
• at least one parameter selected from the parameter group consisting of the pressure of said raw-material gas mixture introduced into said vacuum chamber, the exhaust amount of gas discharged from said vacuum chamber, said high-frequency electric power, the frequency of said high-frequency electric power, the rate of said lateral wall protecting gas in said raw-material gas mixture and the temperature of said sample stand, is changed such that the amounts in which the lateral walls of said first and second line patterns are etched, are decreased and that the amount in which the lateral walls of said first line patterns are etched, is smaller than the amount in which the lateral walls of said second line patterns are etched.

In a dry etching method comprising the steps of:

• introducing, into a vacuum chamber provided at a lower portion thereof with a sample stand, a raw-material gas mixture containing (i) an etching gas for etching a sample to be etched which is placed on said sample stand and in the surface of which a resist pattern is formed, and (ii) a lateral wall protecting gas for generating lateral wall protecting radicals for protecting the lateral walls of line patterns formed when said sample is etched, whereby ions composed of said gas mixture are generated;
• and
• applying a high-frequency electric power to said sample stand to form a self DC bias, thereby to induce said ions to said sample stand, whereby said sample is etched:
• said dry etching method comprising a parameter control step arranged such that,
• when the line width of a first line pattern, which is one of line patterns located at the inner side of a line pattern group comprising a plurality of line patterns adjacent to one another formed in a sample, is greater than the line width of a second line pattern, which is one of outer line patterns located at the outermost side of said line pattern group or one of line patterns located as isolated from said line pattern group, and when the line width of each of said first and second line patterns is greater than the line width of said resist pattern,
• at least one parameter selected from the parameter group consisting of the pressure of said raw-material gas mixture introduced into said vacuum chamber, the exhaust amount of gas discharged from said vacuum chamber, said high-frequency electric power, the frequency of said high-frequency electric power, the rate of said lateral wall protecting gas in said raw-material gas mixture and the temperature of said sample stand, is changed such that the amounts in which the lateral walls of said first and second line patterns are etched, are increased and that the amount in which the lateral walls of said first line patterns are etched, is greater than the amount in which the lateral walls of said second line patterns are etched.

In a dry etching method comprising the steps of:

• introducing, into a vacuum chamber provided at a lower portion thereof with a sample stand, a raw-material gas mixture containing (i) an etching gas for etching a sample to be etched which is placed on said sample stand and in the surface of which a resist pattern is formed, and (ii) a lateral wall protecting gas for generating lateral wall protecting radicals for protecting the lateral walls of line patterns formed when said sample is etched, whereby ions composed of said gas mixture are generated;
• and
• applying a high-frequency electric power to said sample stand to form a self DC bias, thereby to induce said ions to said sample stand, whereby said sample is etched:
• said dry etching method comprising a parameter control step arranged such that,
• when the line width of a first line pattern, which is one of line patterns located at the inner side of a line pattern group comprising a plurality of line patterns adjacent to one another formed in a sample, is greater than the line width of a second line pattern, which is one of outer line patterns located at the outermost side of said line pattern group or one of line patterns located as isolated from said line pattern group, and when the line width of each of said first and second line patterns is smaller than the line width of said resist pattern,
• at least one parameter selected from the parameter group consisting of the pressure of said raw-material gas mixture introduced into said vacuum chamber, the exhaust amount of gas discharged from said vacuum chamber, said high-frequency electric power, the frequency of said high-frequency electric power, the rate of said lateral wall protecting gas in said raw-material gas mixture and the temperature of said sample stand, is changed such that the amounts in which the lateral walls of said first and second line patterns are etched, are decreased and that the amount in which the lateral walls of said first line patterns are etched, is greater than the amount in which the lateral walls of said second line patterns are etched.