A method for forming a photo diode is provided. The present invention is based upon the discovery that when employing ALD techniques to form refractory metal layers on a substrate, the carrier gas employed impacts the presence of fluorine in the resulting layer. Therefore, the expressed transgenes within these transgenic lines mimic antagonist and agonist selectivity of the wild type primate B1 bradykinin receptor. The wiring layer is plated and is made thicker than the shielding layer.