Polycrystalline silicon

About: Polycrystalline silicon is a research topic. Over the lifetime, 19554 publications have been published within this topic receiving 198222 citations. The topic is also known as: polysilicon & poly-Si.

High speed lateral bipolar transistor

Abstract: A bipolar transistor NPN structure (20) is constructed at a major surface of a silicon body with a P-type polycrystalline silicon electrode (13) contacting a P-type base zone (13.6). Excess acceptor impurities from the polycrystalline silicon electrode (13) are diffused into the base zone (13.6) in order to tailor its conductivity profile.

Silver-induced layer exchange for the low-temperature preparation of intrinsic polycrystalline silicon films

Abstract: The preparation of large grained continuous polycrystalline silicon layers by metal-induced crystallization is reported. The macroscopic layer exchange of an amorphous silicon precursor layer in contact with a silver layer was observed for temperatures below the softening point of glass. This process is quite similar to the well-known aluminum-induced layer exchange. However, due to the use of silver as a catalyst, the recrystallized layers are electrically intrinsic rather than highly doped with Al acceptors. The resulting polycrystalline silicon layers show a good crystalline quality as deduced from Raman scattering, x-ray diffraction, and UV-reflectance measurements.

Improvements of on-membrane method for thin film thermal conductivity and emissivity measurements

Abstract: A numerical simulation and various test-structure configurations were developed which enable the measurement of the in-plane thermal conductivity and emissivity of on-membrane thin films in a versatile and accurate manner. The simulation takes into account the two-dimensional heat transfer in the membrane. Consequently, shorter membrane can be used and strained materials can be measured. The numerical simulation along with the new test-structures is used to understand the convective heat transfer at small scales and to quantify it. The measurement method is tested on various materials ranging from ceramics, metals to polycrystalline silicon.

Recrystallization processes in polycrystalline silicon

Abstract: Recrystallization processes in polycrystalline silicon made by a chemical vapor deposition technique have been investigated. Primary recrystallization has been observed between 1150 and 1250 °C, secondary recrystallization occurred above 1350 °C. By this procedure, grains of about 100 μm have been obtained. Recrystallized silicon can in principle be used as a substrate for making relatively inexpensive solar cells.

Polycrystalline silicon formed by ultrahigh‐vacuum sputtering system

Abstract: Using an ultrahigh‐vacuum (UHV) sputtering system, we could grow two new methods of polycrystalline silicon films. The one is as‐deposited polycrystalline silicon on glass at substrate temperatures under 500 °C. The other is solid‐phase‐crystallization by thermal annealing of as‐deposited amorphous silicon films in a UHV. As‐deposited polycrystalline silicon films were oriented to (220) and grain sizes were determined from half‐width of x‐ray diffraction to be about 40 nm. From the deposition temperature dependence of the x‐ray diffraction peak intensity, the activation energy of the crystalline growth was calculated to be about 0.6 eV. Hydrogen atoms in the sputtering gas lower the reproducibility of as‐deposited poly‐Si. Polycrystalline silicon films produced by thermal annealing of as‐deposited amorphous silicon films at 550 °C in UHV have a (111) orientation. Field‐effect mobilities of the as‐deposited polycrystalline silicon film and the polycrystalline silicon film by UHV thermal annealing were 5 an...