Sputtering target and method for manufacturing a sputtering target
Provided a sputtering target and a method for manufacturing the sputtering target, in which a penetration of impurities into the target material during bonding is suppressed A sputtering target, wherein an intensity ratio (B/A) of a minimum reflection intensity B to a maximum reflection intensity A of a back surface wave of a target material as measured by a water immersion ultrasonic flaw detection inspection after bonding the target material is 0.70 or more, and wherein a water absorption rate of the target material determined by a relationship of a weight change rate (100×(a−b)/b) is 0.01% to 1.0%, where (a) is a weight after immersion as measured after immersing the target material in water for 10 hours and removing the water on a surface, and (b) is a dry weight of the target material before the immersion.
1. A sputtering target comprising a target material bonded onto a base material, the target material containing In, Ga, Zn and O,
wherein an intensity ratio (B/A) of minimum reflection intensity B to maximum reflection intensity A of a back surface wave of the target material as measured by a water immersion ultrasonic flaw detection inspection after bonding the target material is 0.70 or more, and wherein a water absorption rate of the target material determined by a relationship of the weight change rate (100×(a−b)/b) is 0.01% to 1.0%, where (a) is a weight after immersion as measured after immersing the target material in water for 10 hours and removing the water, and (b) is a dry weight of the target material before the immersion.
2. The sputtering target according to claim 1 , wherein the target material comprises In, Ga, and Zn, wherein atom ratios for In, Ga, and Zn are:
0.20≤In/(In+Ga+Zn)≤0.70
0.20≤Ga/(In+Ga+Zn)≤0.70 and
0.00<Zn/(In+Ga+Zn)≤0.50
3. The sputtering target according to claim 1 , wherein the target material comprises In, Ga, and Zn, wherein atom ratios for In, Ga, and Zn are:
0.32≤In/(In+Ga+Zn)≤0.36
0.32≤Ga/(In+Ga+Zn)≤0.36 and
0.32≤Zn/(In+Ga+Zn)≤0.36.
4. The sputtering target according to claim 1 , wherein the target material comprises at least one impurity component selected from the group consisting of C, Si, N, and Cl.
5. The sputtering target according to claim 4 , wherein a maximum impurity component value (Cmax) is 30 mass ppm or less for C and 5.0 mass ppm or less for Si, N, and Cl.
6. The sputtering target according to claim 1 , wherein a relative density is 90% or more.