| 摘要 |
<p>An oxide sintered compact composed of a composite oxide of lanthanum and hafnium, wherein the amount of hafnium contained in the sintered compact is equivalent or more relative to the lanthanum. A method of producing an oxide sintered compact of lanthanum and hafnium, wherein La 2 (CO 3 ) 3 powder and HfO 2 powder are used as raw material powder, blending and mixing are performed so that the composition molar ratio of Hf and La becomes 1 to 1.2, the mixed powder is thereafter heated and synthesized in the atmosphere, the synthesized material is subsequently pulverized to obtain powder, and the synthesized powder is thereafter hot pressed into a sintered compact. Since metal lanthanum rapidly bonds with oxygen and decays, and lanthanum oxide bonds with moisture and forms a hydroxide and changes into powder form, there is a problem in that long-term storage is difficult and a sputtering target cannot be used for a practical use. In light of these points, provided is a stable La-containing oxide sintered compact composed of oxides of lanthanum (La) and hafnium (Hf), and in particular provided is a La-containing oxide sputtering target that is suitable for forming a high-k gate insulating film.</p> |
