Effects of finger dimension on low-frequency noise and optoelectronic properties of Ge metal-semiconductor-metal photodetectors with interdigitated Pt finger electrodes. (February 2017)

• Record Type: Journal Article
• Authors: Zumuukhorol, Munkhsaikhan; Khurelbaatar, Zagarzusem; Yuk, Shim-Hoon; Won, Jonghan; Lee, Sung-Nam; Choi, Chel-Jong
• Is Part Of: Microelectronics and reliability. Volume 69(2017)
• Page Start: 60
• Page End: 65
• Publication Date: 2017-02
• Subjects: Ge MSM photodetector -- Dark current -- NPDR -- 1/f noise -- Electric field crowding -- Current crowding; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2016.12.001
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: We investigated the effect of interdigitated Pt finger electrode dimension on the low-frequency noise and optoelectrical properties of Ge metal-semiconductor-metal (MSM) infrared photodetectors (PDs). This dark current reduction led to an increase in the normalized photo current to dark current ratio (NPDR). The decrease in finger width/spacing facilitated the occurrence of the electric field crowding near contact electrode. This resulted in the image-force Schottky barrier lowering, which could be responsible for the increase in dark current. From the low frequency noise measurements performed at the frequencies in the range of 10 Hz–1 kHz, the Ge MSM PDs had 1/ f γ frequency dependence with γ ranging from 1.07 to 1.20, regardless of finger dimension. The current crowding, in particular at the vicinity of the finger electrodes, was more pronounced in the Ge MSM PDs having smaller finger width/spacing, which could be a main cause of the increase in the low frequency noise. Highlights: Effect of finger geometry on 1/ f noise and NPDR of Ge MSM PDs was investigated. Smaller finger width/spacing leads to higher current crowding and electric field crowding. Reduction of dark current lead to an increase in NPDR. Electric field crowding causes the increase in dark current. Current crowding serve as a main source of 1/ f noise.