Process for producing crystalline ceric oxide particles and abrasive
AssigneeNissan Chemical Industries, Ltd.
InventorsToshio Kasai, Isao Ota, Takao Kaga, Tohru Nishimura, Kenji Tanimoto
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Abstract
According to the present invention, a process is provided for producing crystalline ceric oxide particles having a particle diameter of 0.005 to 5 .mu.m, which comprises the steps of reacting a cerium (III) salt with an alkaline substance in an (OH)/(Ce.sup.3+) molar ratio of 3 to 30 in an aqueous medium in an inert gas atmosphere to produce a suspension of cerium (III) hydroxide, and blowing oxygen or a gas containing oxygen into the suspension at a temperature of 10 to 95.degree. C. and at an atmospheric pressure.
Claims12
A process for producing crystalline ceric oxide particles having a particle diameter of 0.005 to 5 .mu.m comprising the steps of:
- reacting a cerium (III) salt with an alkaline substance in an (OH)/(Ce.sup.3+) molar ratio of 3 to 30 in an aqueous medium in an inert gas atmosphere to produce a suspension of cerium (III) hydroxide, and
- immediately blowing oxygen or a gas containing oxygen into the suspension at a temperature of 10 to 95.degree. C. and at an atmospheric pressure.
An abrasive composed of ceric oxide particles heated at a temperature of 50 to 250.degree. C. in an aqueous medium in the presence of an ammonium salt.
A polishing method using an abrasive composed of ceric oxide particles heated at a temperature of 50 to 250.degree. C. in an aqueous medium in the presence of an ammonium salt.
A polishing method using an abrasive composed of ceric oxide particles heated at a temperature of 50 to 250.degree. C. in an aqueous medium in the presence of ammonium carbonate, ammonium hydrogencarbonate or a mixture thereof.
A method of polishing a semiconductor device using an abrasive composed of ceric oxide particles heated at a temperature of 100 to 250.degree. C. in an aqueous medium in the presence of ammonium nitrate, ammonium sulfamate or a mixture thereof.
A method of polishing a semiconductor device using a first abrasive and a second abrasive, alternately, wherein said first abrasive is an abrasive composed of ceric oxide particles heated at a temperature of 50 to 250.degree. C. in an aqueous medium in the presence of ammonium carbonate, ammonium hydrogencarbonate or a mixture thereof, and wherein said second abrasive is an abrasive composed of ceric oxide particles heated at a temperature of 50 to 250.degree. C. in an aqueous medium in the presence of ammonium nitrate, ammonium sulfamate or a mixture thereof.
Dependencies are inferred from the claim text.