Preparation technology of tantalum target material. In the process of preparing tantalum targets, the tantalum powder is first formed by isostatic pressing to obtain tantalum billet, and then the tantalum billet is sintered, rolled and heat treated to obtain tantalum target. In this application, high-performance tantalum target blank is prepared by powder metallurgy method, and then through pressure processing and corresponding heat treatment process, tantalum target meets the semiconductor application. The tantalum target prepared by this method meets the following two requirements: the grain size is less than 60μm, the tantalum target has the same thickness direction uniformity, and the grain size range is less than 15μm; The three kinds of texture components are uniform, and there is no strong texture component. Specifically, the powder metallurgy method is used to prepare high-performance tantalum target blank. The powder is first pressed into a block by mechanical external force, and then through sintering, the mechanical bond between the powder particles of the pressed block becomes a metal bond and becomes a metal raw material. In this process, due to the small particle size of the original powder particles and the small grain growth degree during the sintering process, the mechanical bond between the powder particles becomes a metal raw material. The grain size of the billet is much smaller than that of the smelting ingot, and the grain size is less than 60μm, and the range is less than 15μm. At the same time, the structure of the billet prepared by powder metallurgy is uniform, which is much better than that of the smelting ingot, because the forming conditions at each position of the billet are the same. The raw grain size and texture distribution of the billet used in this application are very uniform; The purpose of the late pressure processing is to form, and there is only one pressure processing process of rolling, which has little effect on the texture uniformity. Therefore, the three kinds of tantalum targets with uniform texture components and no strong texture components can be prepared by this method.
Tantalum blank was obtained by cold isostatic pressing. The size of latex sheath was Φ270mm×350mm. The cold isostatic pressing pressure was 250MPa and the holding time was 60min. The tantalum billet was sintered by graphite heating furnace. The vacuum degree was >1.0*10-2MPa, the temperature was 2600℃, and the holding time was 2 hours.
The tantalum billet with Φ265mm×δ50mm was obtained by removing the defects after sintering. The tantalum billet is rotated and rolled to Φ375mm×δ25mm; The tantalum billet is heat treated at 1300℃ and the holding time is 90min. The tantalum billet after heat treatment is rotated again and rolled to Φ470mm×δ16mm; Tantalum target material was obtained by heat treatment of rolled tantalum billet at 1100℃ and holding time for 90min. The tantalum billet with Φ175mm×δ50mm was obtained by removing the defects after sintering. The tantalum billet is rotated and rolled to Φ250mm×δ24mm; The tantalum billet is heat treated at 1300℃ and the holding time is 90min. The tantalum billet after heat treatment is rotated again and rolled to Φ360mm×δ11mm; Tantalum target material was obtained by heat treatment of rolled tantalum billet at 1100℃ and holding time for 90min.
