Provided is a method of fabricating a semiconductor package. The method include providing a lower package with an inner solder ball, providing a conductive material on the inner solder ball to form an outer solder ball enclosing the inner solder ball, providing an upper package with an upper solder ball, on the lower package, performing a first process at a first temperature to join the upper solder ball to the outer solder ball, and performing a second process at a second temperature to unite the upper, inner, and outer solder balls into a connection terminal.