Purpose. Development of a new design and original technology for manufacturing an avalanche silicon photodiode with an operating absorption wavelength of 1.06μm and a sensitivity of no worse than 40A/W.
Specifications.
- Planar diffusion FS (front) and BS (reverse) with design standards of no more than 1 µm.
- Number of polysilicon layers – 1.
- Number of metallization layers – 2.
- Supply voltage – up to 400V.
Application area. Development and production of special-purpose instrumentation.
Advantages. The main advantage of this technology is the high sensitivity of photodiodes with reduced noise levels.
Technical and economic effect. The estimated annual demand for the production of avalanche silicon photodiodes is approximately 5,000 pcs. in year. The costs of introducing the technology into mass production are estimated at UAH 48 million.
Description. Replacing the emitter region highly doped with arsene with a deposited highly doped polysilicon layer, which makes it possible to reduce the concentration of defects in the space charge region, and also reduces the parasitic effects of short-wave radiation, the formation of a meta-surface coating in the form of periodic 1D/2D metal gratings for focusing radiation.
Modified technology for forming silicon PIN photodiodes, which uses:
- a deep ion-implanted impurity layer of the same type of conductivity as the high-resistivity substrate;
- a layer of doped polycrystalline silicon as a short-wave filter and a source of shallow pn junction, which is located above the deeply implanted impurity and does not reach it;
- mesa pn junction structure reaching the maximum concentration level of the deep ion-implanted layer in a highly doped silicon substrate;
- charge control at the dielectric-silicon interface; formation of a relief on the back side of the photodiode and (or) on the polysilicon layer.