Manufacturing method for semiconductor device

A method for producing a semiconductor device including an oxide semiconductor TFT, comprising the steps of:

• preparing an insulating substrate;
• and
• forming an oxide semiconductor layer on the insulating substrate;
• wherein:
• the step of forming the oxide semiconductor layer includes the step of sputtering a target;
• the target includes a plurality of target tiles located while having a gap therebetween;
• at least one backing plate for supporting the plurality of target tiles;
• and at least one bonding member provided between the at least one backing plate and the plurality of target tiles;
• and
• the plurality of target tiles each contain In, Ga and Zn;
• and when the target is seen in a direction normal thereto from the side on which the plurality of target tiles are located, the plurality of target tiles are each smaller than the insulating substrate, and the at least one bonding member cannot be seen through the gap.