CN-115109565-B - Polishing composition, polishing method, and method for producing semiconductor substrate

Abstract

The present invention relates to a polishing composition, a polishing method, and a method for manufacturing a semiconductor substrate. Provided is a polishing composition which can polish a layer having a group 13 element content of 40 mass% or more at a high polishing rate. Provided is a polishing composition for polishing an object to be polished, which comprises a layer having a group 13 element content of more than 40 mass%, wherein the polishing composition comprises a cationically modified silica, a polyalkylene glycol, and an acid.

Inventors

• YOSHIZAKI YUKINOBU
• IKAWA HIROFUMI

Assignees

• 福吉米株式会社

Dates

Publication Date

20260508

Application Date

20220317

Priority Date

20210319

Claims (12)

1. 1. A polishing composition for polishing an object to be polished having a layer containing 40 mass% or more of a group 13 element, The polishing composition comprises a cationically modified silica, a polyalkylene glycol and an acid, The pH of the polishing composition is 3 or less, The Zeta potential of the cationic modified silica is 5mV or more and 60mV or less.
2. 2. The polishing composition according to claim 1, wherein the cationic modified silica is obtained by immobilizing a silane coupling agent having an amino group or a silane coupling agent having a quaternary ammonium group on the surface of silica.
3. 3. The polishing composition according to claim 1 or 2, wherein the average primary particle diameter of the cationically modified silica is 5nm or more and 30nm or less.
4. 4. The polishing composition according to claim 3, wherein a ratio of an average secondary particle diameter of the cation-modified silica to the average primary particle diameter of the cation-modified silica, that is, an average secondary particle diameter/average primary particle diameter is 1.2 or more and 3 or less.
5. 5. The polishing composition according to claim 1 or 2, wherein the polyalkylene glycol is polyethylene glycol.
6. 6. The polishing composition according to claim 1 or 2, wherein the polyalkylene glycol has a weight average molecular weight of 100 or more and 30000 or less.
7. 7. The polishing composition according to claim 1 or 2, wherein the acid is at least 1 selected from the group consisting of an acid having a nitric acid group and an acid having a sulfonic acid group.
8. 8. The polishing composition according to claim 1 or 2, wherein the dispersion medium is composed of only water.
9. 9. The polishing composition according to claim 1 or 2, wherein the polyalkylene glycol has a weight average molecular weight of 150 to 350.
10. 10. The polishing composition according to claim 7, wherein the acid has a sulfonic acid group.
11. 11. A polishing method comprising the step of polishing an object to be polished having a layer containing 40 mass% or more of a group 13 element by using the polishing composition according to any one of claims 1 to 10.
12. 12. A method for producing a semiconductor substrate, comprising polishing a semiconductor substrate having a layer containing 40 mass% or more of a group 13 element by the polishing method according to claim 11.

Description

Polishing composition, polishing method, and method for producing semiconductor substrate Technical Field The present invention relates to a polishing composition, a polishing method, and a method for manufacturing a semiconductor substrate. Background In recent years, with the multilayer wiring of the surface of a semiconductor substrate, a so-called Chemical Mechanical Polishing (CMP) technique has been used in which the semiconductor substrate is polished to be planarized in the manufacture of devices. CMP is a method of planarizing the surface of an object to be polished (object to be polished) such as a semiconductor substrate, which is silicon, polysilicon, a silicon oxide film (silicon oxide), silicon nitride, wiring formed of metal, plugs, or the like, using a polishing composition (slurry) containing abrasive grains such as silicon dioxide, aluminum oxide, cerium oxide, or the like, an anticorrosive agent, a surfactant, or the like. For example, japanese patent application laid-open No. 2007-103515 (corresponding to the specification of U.S. patent application publication No. 2007/0077764) discloses a polishing method comprising a step of pre-polishing with a pre-polishing composition containing abrasive grains, an alkali, a water-soluble polymer and water, and a step of finish polishing with a finish polishing composition containing abrasive grains, an alkali, a water-soluble polymer and water, as a technique for polishing a polysilicon film provided on a silicon substrate having a separation region. Disclosure of Invention Problems to be solved by the invention Recently, as a semiconductor substrate, a substrate having a layer containing 40 mass% or more of a group 13 element is used, and new requirements for polishing the substrate have been proposed. Such requirements have not been substantially studied in the past. Accordingly, an object of the present invention is to provide a polishing composition capable of polishing a layer having a group 13 element content of 40 mass% or more at a high polishing rate. Another object of the present invention is to provide a polishing composition in which a polishing rate of a layer containing a group 13 element in an amount of 40 mass% or more is higher than that of other materials (i.e., a high selectivity). Solution for solving the problem In order to solve the above-described new problems, the present inventors have conducted intensive studies. As a result, the present inventors have found that the above problems can be solved by a polishing composition comprising a cationically modified silica, a polyalkylene glycol and an acid, and have completed the present invention. Specifically, the present invention is a polishing composition for polishing an object to be polished, the polishing composition comprising a cationically modified silica, a polyalkylene glycol, and an acid, the polishing composition having a layer containing a group 13 element in an amount of 40 mass% or more. Detailed Description The present invention provides a polishing composition for polishing an object to be polished, the polishing composition comprising a cationically modified silica, a polyalkylene glycol, and an acid, the polishing composition having a layer containing a group 13 element in an amount of 40 mass% or more. The polishing composition according to an embodiment of the present invention having such a constitution can polish a layer having a group 13 element content of 40 mass% or more at a high polishing rate. In addition, the polishing composition according to another embodiment of the present invention has a higher polishing rate (i.e., a higher selection ratio) for a layer containing 40 mass% or more of group 13 element than for other materials. Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments. In the present specification, unless otherwise specified, measurement of the operation, physical properties, and the like is performed under the conditions of room temperature (20 ℃ or more and 25 ℃ or less)/relative humidity 40% RH or more and 50% RH or less. [ Polishing object ] The object to be polished of the present invention has a layer containing 40 mass% or more of a group 13 element (hereinafter, also simply referred to as a group 13 element layer). Examples of the group 13 element include boron (B), aluminum (Al), gallium (Ga), and indium (In). The group 13 elements may be 1 kind alone, or 2 or more kinds in combination. The group 13 element layer may contain other elements than the group 13 element. Examples of the other element include silicon (Si), hydrogen (H), nitrogen (N), oxygen (O), carbon (C), phosphorus (P), and germanium (Ge). These other elements may be contained in 1 kind alone, or in combination of 2 or more kinds. The lower limit of the amount of the group 13 element contained in the group 13 element layer is 40 mass% or more, preferably 45 mass% or more, more pre