A novel LDNMOS embedded silicon controlled rectifier(SCR) was proposed to enhance ESD robustness of high-voltage(HV) LDNMOS based on a 0.5 μm 18 V CDMOS process. A two-dimensional(2D) device simulation and a transmission line pulse(TLP) testing were used to analyze the working mechanism and ESD performance of the novel device. Compared with the traditional GG-LDNMOS, the secondary breakdown current(It2) of the proposed device can successfully increase from 1.146 A to 3.169 A with a total width of 50 μm, and ESD current discharge efficiency is improved from 0.459 m A/μm2 to 1.884 m A/μm2. Moreover, due to their different turn-on resistances(Ron), the device with smaller channel length(L) owns a stronger ESD robustness per unit area.
A new complementary metal oxide semiconductor UV/blue-extended photodiode was presented for light detection in the UV/blue spectral range. Photoelectric characteristics of this presented photodiode were studied by numerical modeling and device simulation. Technology computer aided design simulation was done first to analyze its photoelectric characteristics. The structure characteristic and depletion situation of space between two adjacent P+ anodes were discussed. The reverse characteristic, spectral response characteristic and DC characteristic were discussed in detail. For the numerical modeling, dead layer effect is considered in the building of analytical mode. Dead layer is a space in which the boron doping profile decreases towards the surface due to high doping effects and boron redistribution, which affects the sensitivity of photodiode in the UV range seriously. Reverse characteristics and spectral response characteristics were modeled and analyzed typically. At last, silicon test results were given and compared with the simulated result, which shows reasonable match for each.
