LED ARRAY FOR OPTICAL PRINTING HEAD AND OPTICAL PRINTING HEAD USING THE ARRAY

摘要

PROBLEM TO BE SOLVED: To prevent the component of a semiconductor substrate material from diffusing and reaching the surface electrode layer by further providing an adherence metal layer and a diffusion preventive layer in the order from the ohmic metal layer side between the ohmic metal layer and surface electrode forming a common electrode. SOLUTION: The LED(light emitting diode) array 101 is provided with a surface electrode (an Au layer) consisting of Ti and a diffusing preventive layer 20d consisting of Pt in the order from an ohmic metal layer 20a side between the ohmic metal layer (an AuGeNi layer) 20a and a surface electrode layer (an Au layer). The ohmic metal layer 20a, surface metal electrode layer 20b, adherence metal layer 20c and diffusion preventive metal layer 20d constitutes a common electrode 20. In this constitution, due to Pt 20d, GaAs is prevented from diffusing and reaching the Au layer 20b from the GaAs substrate 10a as an undercoat, thereby enhancing an excellent adherence of Pt layer 20d by the Ti layer 20c.