Polishing composition

• US 6,398,827 B1
• Filed: 06/29/2000
• Issued: 06/04/2002
• Est. Priority Date: 07/02/1999
• Status: Expired due to Fees

• Current Assignee: Nissan Chemical Industries Limited (Shin-Etsu Chemical Company Limited)
• Original Assignee: Nissan Chemical Industries Limited (Shin-Etsu Chemical Company Limited)
• Inventors: Ohmori, Yutaka, Ema, Kiyomi, Ota, Isao, Nishimura, Tohru, Kashima, Yoshiyuki, Watanabe, Yoshitane
• Primary Examiner(s): Marcheschi, Michael
• Application Number:
  US09/605,542
• Time in Patent Office: 705 Days
• Field of Search: 513/08, 106/3, 438/692, 438/693, 510/165, 510/167, 510/397
• US Class Current: 51/308
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/1463 Aqueous liquid suspensions

Abstract

The present invention relates to a polishing composition for polishing alumina disks, polishing substrates having silica surfaces and semiconductor wafers, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D₁/D₂) of a particle diameter D₁ nm (as measured by dynamic light scattering method) to a mean particle diameter D₂ (as measured by nitrogen absorption method) of 3 or more, wherein D₁ is between 50 to 800 nm and D₂ is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked together in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition contains 0.5 to 50% by weight of said moniliform colloidal silica particles.

Claims

1. A polishing composition for polishing alumina disks, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D₁/D₂) of a particle diameter D₁ nm (as measured by dynamic light scattering method) to a mean particle diameter D₂(as measured by nitrogen adsorption method) of 3 or more, wherein D₁ is between 50 to 800 nm and D₂ is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked together in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition containing 0.5 to 50% by weight of said moniliform colloidal silica particles.

2. The polishing composition according to claim 1, further comprising 0.01 to 5.0% by weight, expressed as an Fe₂O₃ concentration, of at least one iron compound selected from the group consisting of iron (III) nitrate, iron (III) chloride, iron (III) sulfate, and potassium iron (III) sulfate.

3. A polishing composition for polishing substrates having silica surfaces, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D₁/D₂) of a particle diameter D₁ nm (as measured by dynamic light scattering method) to a mean particle diameter D₂ (as measured by nitrogen adsorption method) of 3 or more, wherein D₁ is between 50 to 800 nm and D₂ is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond, which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked together in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition contains 0.5 to 50% by weight of said moniliform colloidal silica particles.

4. A polishing composition for polishing semiconductor wafers, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D₁/D₂) of a particle diameter D₁ nm (as measured by dynamic light scattering method) to a mean particle diameter D₂ (as measured by nitrogen adsorption method) of 3 or more, wherein D₁ is between 50 to 800 nm and D₂ is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition comprises 0.5 to 50% by weight of said moniliform colloidal silica particles.