HEAT oven to 450°F.
PLACE pizza crust on baking sheet; sprinkle with 1/2 cup mozzarella.
TOSS chicken with barbecue sauce; spoon onto crust. Top with feta, onions and remaining mozzarella.
BAKE 10 to 12 min. or until mozzarella is melted and crust is golden brown. Let stand 5 min. before cutting to serve.