Plazmonik yapılarla geliştirilmiş silikon kızılötesi schottky algılayıcı

The holy grail of near infrared (NIR) photonics is a purely-Silicon-based solution. Today, infrared detection is dominated by III-V compound semiconductors, mainly InGaAs devices in the NIR. The high cost of integration with established Si VLSI technology, prevent the market growth of compound semiconductor device technology despite high efficiencies attained. On the other hand, Silicon is the second most abundant element on the earth and is the predominant material of the complementary metal-oxide-semiconductor (CMOS) technology. Since Silicon is near infrared blind due to its large energybandgap (~1.12 eV) it cannot absorb infrared light efficiently. However, Silicon based Schottky photodetectors can operate at infrared wavelengths due to their absorption mechanism at the interface of metal and semiconductor. The metal-semiconductor (M-S) diode is among the most investigated junction devices. Schottky diodes have been very attractive for their high speeds. The potential of high frequency operation and the ease of integration render Schottky devices a strong candidate in CMOS compatible NIR photonics. Silicon based Schottky photodetectors can be a promising candidate if NIR efficiencies could be increased. We design, fabricate and characterize plasmonic gratings to increase the efficiency of Silicon based Schottky photodetectors at the near infrared region. Our design is optimized for the conventional telecommunication C-band (1530 nm-1650 nm). We also study the effects of an interlayer dielectric and metal layer on the plasmonic fields. We use atomic layer deposited Alumina (Al2O3) between the metal and the semiconductor at the M-S junction. Our micro/nano-fabricated photodetector devices exhibit low dark current densities (~21 mA/cm2 at -3 V) and high responsivity values (~83 mA/W at 1530 nm and -3V). Plasmonic gratings provide an increase of responsivity by more than a factor of 2 at desired wavelengths.