Polishing medium for chemical-mechanical polishing, and method of polishing substrate member

A method of polishing a substrate member having a barrier layer containing at least one of tantalum, a tantalum alloy and a tantalum compound overlying an insulator and a conductor layer containing at least one of copper, a copper alloy and copper oxide on the barrier layer, comprising:

• chemical-mechanical polishing the conductor layer, using a first chemical-mechanical polishing medium, so as to remove portions of the conductor layer and expose portions of the barrier layer, in a first step;
• and
• thereafter, chemical-mechanical polishing exposed portions of the barrier layer, using a second chemical-mechanical polishing medium, wherein the second chemical-mechanical polishing medium comprises:
• an oxidizing agent;
• a protective-film-forming agent;
• an acid;
• and
• water, wherein:
• said polishing medium has a pH of 3 or less, and
• said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight.

A method of polishing a substrate member comprising a step of polishing a surface including a wiring layer and a barrier layer, by applying to the surface a polishing medium for chemical-mechanical polishing, adapted to polish a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a wiring layer of copper, copper alloy, or copper oxide, said polishing medium comprising:

• an oxidizing agent;
• a protective-film-forming agent;
• an acid;
• and
• water, wherein:
• said polishing medium does not include abrasive grains,
• said polishing medium has a pH of 3 or less, and
• said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight, and wherein:
• as a polishing condition, polishing pressure is 25 kPa and relative speed of substrate member to polishing platen is 18 m/minute, the polishing medium for chemical-mechanical polishing has:
• a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1;
• a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1;
• a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10;
• and
• a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide film of more than 10.

A method of polishing a substrate member comprising a step of polishing a barrier layer containing tantalum, a tantalum alloy or a tantalum compound, by applying to the barrier layer a polishing medium for chemical-mechanical polishing, adapted to polish a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a conductor of copper, copper alloy, or copper oxide, the polishing medium comprising:

• an oxidizing agent;
• a protective-film-forming agent;
• abrasive grains;
• an acid;
• and
• water, wherein:
• said polishing medium has a pH of 3 or less, and
• said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight;
• and wherein:
• as a polishing condition, polishing pressure is 25 kPa and relative speed of substrate member to polishing platen is 18 m/minute, the polishing medium has:
• a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1;
• a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1;
• a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10;
• and
• a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide film of more than 10.

A method of polishing a substrate member comprising a step of polishing a surface including a wiring layer and a barrier layer, by applying to the surface a polishing medium for chemical-mechanical polishing, adapted to polish a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a conductor of copper, copper alloy, or copper oxide, the polishing medium comprising:

• an oxidizing agent;
• a protective-film-forming agent;
• abrasive grains;
• an acid;
• and
• water, wherein:
• said polishing medium has a pH of 3 or less, and
• said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight;
• and wherein:
• as a polishing condition, polishing pressure is 25 kPa and relative speed of substrate member to polishing platen is 18 m/minute, the polishing medium has:
• a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1;
• a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1;
• a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10;
• and
• a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide film of more than 10.