Sintered compact magnesium oxide target for sputtering, and method for producing same

Patent metadata

Field	Value
Publication number	US-10066290-B1
Application number	US-201815969958-A
Country	US
Kind code	B1
Filing date	May 3, 2018
Priority date	Dec 27, 2011
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A sintered compact magnesium oxide target for sputtering has a purity of 99.99 wt % or higher excluding C, a density of 3.57 g/cm 3 or higher, and a whiteness of 60% or less. To uniformly deposit a magnesium oxide film, a magnesium oxide target having a higher purity and a higher density is demanded. An object is to provide a target capable of realizing the above and a method for producing such a target. While a magnesium oxide sintered compact sputtering target is produced by hot-pressing a raw material powder, there is a problem in that color shading occurs in roughly φ60 (within a circle having a diameter of 60 mm) at the center part of the target. Conventionally, no particularly attention was given to this problem. However, in recent years, it has become necessary to investigate and resolve this problem in order to improve the deposition quality.

First claim

We claim:

1. A method for producing a sputtering target comprising a sintered compact of magnesium oxide, comprising the steps of:
adding raw material powder of MgCO 3 in an amount of 5 wt % or more and less than 30 wt % to raw material powder of magnesium oxide (MgO), the raw material powders of magnesium oxide (MgO) and MgCO 3 having a purity of 99.99 wt % or higher excluding C and an average grain size of 0.5 μm or less;
mixing the raw material powder of MgCO 3 with the raw material powder of magnesium oxide (MgO) to produce a mixture; and
hot pressing the mixture at a temperature of 1500° C. or less and an applied pressure of 300 kgf/cm 2 or more to obtain a sintered compact of magnesium oxide having a purity of 99.99 wt % or higher excluding C, a density of 3.57 g/cm 3 or higher, and a whiteness of 60% or less.

Assignees

• Jx Nippon Mining & Metals Corp

Inventors

• Hisano Akira
• Nakamura Yuichiro

Classifications

• C04B2235/81

  Materials characterised by the absence of phases other than the main phase, i.e. single phase materials · CPC title

• C04B35/053 Primary

  Fine ceramics · CPC title

• C04B2235/9646

  Optical properties · CPC title

• C23C14/3414

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title

• C04B2235/442

  Carbonates · CPC title