Ultralow-capacitance lateral p-i-n photodiode in a thin c-Si film

Abstract

Results of a large-area ultralow-capacitance lateral p-i-n photodiode in a thin crystalline silicon (c-Si) film are presented. Silicon-on-insulator wafers are used for manufacturing of this photodiode. The ultralow-capacitance photodiode possesses and antireflection coating optimized for blue light and is, therefore, appropriate for scintillation detector applications. An external quantum efficiency of 78% and 67.0% is achieved for wavelengths of 430 and 400 nm, respectively. The rise and fall times of the lateral p-i-n photodiode for light with a wavelength of 400 nm are 10.9 and 11.5 ns, respectively. A capacitance of 1.47 pF was measured inclusive of the bondpad capacitance for the lateral p-i-n photodiode with an area of 3.66 mm/sup 2/. The capacitance of the lateral thin-film photodiode alone is actually only 0.61 pF. This photodiode combines an ultralow capacitance with a high quantum efficiency and a high speed.