Every time I need deal with carrier, my viking attacks interceptors automatically instead of attack Carrier. Is there any way to avoid it?
Target fire ??? Vikings are trash, they die to storms, or archons. You need to get bcs, but it is tough, you are behind in economy. If you try to transition into bcs, protoss just kills you. However it may work in lower leagues. Thors are good, but they suck, if protoss build disruptors, or immortals zealots…
maybe use the liberators as a backup instead ? Or try to get interceptors flying, then fire with liberators at the interceptors, they have good area of effect.
Or you are attack-moving and expect the vikings to ignore the interceptors ?!
What others have said. You have to target fire meaning click on the carrier after selecting your troops to attack. If you tell them to attack move, they will always fight what can fight them. Carriers themselves do not attack so no unit prioritizes it.
shift+right button on every carrier, that way once you destroy one carrier your vikings will start hitting the next one.