The invention provides a semiconductor X-ray detector and a manufacturing method of a semiconductor device. A PIN contact layer via hole is located on the side of a pixel unit, therefore the influence of an indium column (comprising a UBM adhering layer) packaging technology on the electrical properties of a PIN diode device can be reduced, a metal stinging phenomenon is avoided, and leakage currents are reduced. Moreover, through adoption of a side edge contact structure, the bad influence of the PIN contact layer via hole on a follow-up indium column pelletizing technology can be reduced. Moreover, through adoption of side edge contact, the metal contact area is reduced, and the metal electric leakage is reduced.