Wavelength [nm]Photon Energy [eV] Depth from Si Surface [nm] Si depth where integrated amount of light decreases to

No abstract

In this paper, we demonstrate two types of new photodiode array (PDA) with fast readout speed and high stability to ultraviolet (UV) light exposure. One is a high full well capacity sensor specialized for absorption spectroscopy, the other one is a high sensitivity sensor for emission spectroscopy. By introducing multiple readout paths along the long side of the rectangle PD, both two PDAs have achieved more than 150 times faster readout speed compared with a general PDA structure with a single readout path along the short side of PD. By introducing a photodiode (PD) structure with a thin and steep dopant profile p + layer formed on a flattened Si surface, a higher stability of the light sensitivity to UV light exposure was confirmed compared with a general PD structure for conventional PDAs.

In this work, by optimizing the structure and thickness of the on-chip multilayer dielectric stack using SiO 2 and low extinction coefficient Si 3 N 4 with the high UV-light sensitivity photodiode technology, high external Q.E. and high stability to UV-light were both successfully obtained. By changing the structure of on-chip multilayer dielectric stack and film thickness, we obtained the photodiode with the high external Q.E. in the desired UV-light region.

High-k oxide material with a high capacitance density, low leakage current density, high-dielectric breakdown voltage and small quadruple voltage coefficient of the capacitance is important for on-chip metal-insulator-metal (MIM) capacitors as well as gate insulators for semiconductor power devices. So in order to improve the quality of such films, a post-deposition process, such as annealing is expected to be effective. In this paper, we carried out various annealing steps after deposition of Al2O3 films with thermal ALD. The electrical characteristics of these Al2O3 films were evaluated. Annealing was proven to be effective in improving the Al2O3 film quality decrease the leakage current and the fixed charge. For O2 annealing at 400°C of MIM capacitor structures containing Al2O3 films deposited with thermal ALD using H2O at a relatively low temperature of 75°C. We achieved a leakage current density of 10-9A/cm2 level and a capacitance density above 10fF/μm2. However, it it is necessary to improve the voltage dependence of the capacitance. For future optimization not only the post-deposition process should be investigated but also the ALD deposition itself, including the selection of the oxidizing co-reactant.