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.

cw laser recrystallization of 〈100〉 Si on amorphous substrates

Abstract: A polycrystalline silicon film 0.55 μm thick was deposited in a low‐pressure CVD reactor on a Si3N4 substrate. Islands of various sizes (2×20 μm up to 20×160 μm) were prepared by standard photolithographic techniques. Laser annealing was then performed under conditions which are known to cause an increase in grain size from ∼500 A to long narrow crystals of 2×25 μm in a continuous polysilicon film. These same conditions were found to produce single‐crystal 〈100〉 material in the (2×20 μm) islands. However, 25×25‐μm and 20×160‐μm islands remain polycrystalline after the laser scan.

Quantitative chemical topography of polycrystalline Si anisotropically etched in Cl2/O2 high density plasmas

Abstract: The spatially resolved surface chemical composition or ‘‘chemical topography’’ of submicron features [polycrystalline silicon (poly‐Si) masked with photoresist (PR) lines] etched in high density, low pressure helical resonator Cl2/O2 plasmas has been quantitatively determined using angle resolved x‐ray photoelectron spectroscopy (XPS). The chemical topography of plasma etched microelectronic materials is important in understanding how impinging ions and neutrals interact with surfaces to influence etched profiles. The spatial origin of XPS signals was determined from a combination of geometric shadowing of photoelectrons by adjacent features, electrostatic charging of insulating surfaces, XPS signal calibration versus take‐off angle, x‐ray attenuation, and geometric modeling. Equal line and space width (0.75–2.0 μm) features, unmasked poly‐Si, and unpatterned PR surfaces were examined following plasma etching and vacuum sample transfer. For pure Cl2 plasmas, Cl surface concentration was found to be similar for horizontal and vertical surfaces of the poly‐Si and PR. Only a small amount of Si was found on the PR sidewall, and similarly, little C or O was observed on the side of the poly‐Si features, indicating that sidewall passivation is not occurring. O coverage on all surfaces increased with O2 addition to the plasma. For Cl2/5% O2 plasmas, a small amount of O was found on the poly‐Si trench bottom, and more (but still submonolayer) on the poly‐Si sidewall. Also, more Cl, O, and Si were found on the PR sidewall with 5% O2. For Cl2/10% O2 plasmas, rough surfaces were observed by scanning electron microscopy (SEM). On poly‐Si trench bottoms, O coverage is comparable to Cl at roughly a monolayer. On poly‐Si sidewalls, O and Cl coverages are again comparable, but the O coverage is about double that found on the trench bottoms. The most dramatic effect by far at 10% added O2 is the formation of a thick SiOx Cly layer (where x≊y≊1) on the side of the PR, detected by both XPS and SEM. The quantitative analysis method developed in this study is readily applicable to other etching gases and materials.The spatially resolved surface chemical composition or ‘‘chemical topography’’ of submicron features [polycrystalline silicon (poly‐Si) masked with photoresist (PR) lines] etched in high density, low pressure helical resonator Cl2/O2 plasmas has been quantitatively determined using angle resolved x‐ray photoelectron spectroscopy (XPS). The chemical topography of plasma etched microelectronic materials is important in understanding how impinging ions and neutrals interact with surfaces to influence etched profiles. The spatial origin of XPS signals was determined from a combination of geometric shadowing of photoelectrons by adjacent features, electrostatic charging of insulating surfaces, XPS signal calibration versus take‐off angle, x‐ray attenuation, and geometric modeling. Equal line and space width (0.75–2.0 μm) features, unmasked poly‐Si, and unpatterned PR surfaces were examined following plasma etching and vacuum sample transfer. For pure Cl2 plasmas, Cl surface concentration was found to be simila...

Preparation of Polycrystalline Silicon by Hydrogen-Radical-Enhanced Chemical Vapor Deposition

Abstract: The preparation of both amorphous and epitaxial crystalline silicon films by Hydrogen-Radical-Enhanced Chemical Vapor Deposition at variable hydrogen flow rates is discussed. The feasibility of fabricating polycrystalline Si at high growth rates and a low substrate temperature is demonstrated. Finally, the n-type characteristics of PH3 doping and p-type characteristic for BF3 doping are examined in terms of the conductivity and the Hall mobility of the films.

Process for preparing a silicon carbide device

Abstract: A silicon carbide layer(s) is provided on a silicon substrate. If necessary, a desired pattern of the silicon carbide layer(s) is allowed to remain, while the other portion(s) is embedded with SiO2. If necessary, the silicon carbide layer(s) may be constituted of a barrier layer and a device-forming layer. A layer capable of easily forming an insulating layer, such as a polycrystalline silicon layer, is provided on the silicon carbide layer to form first electrodes, followed by insulation of the surface, such as oxidation of the surfaces of the first electrodes and the silicon carbide layer. Second electrodes are further formed in self alignment by utilizing the insulating layer of the surface of the first electrodes. This process is useful in preparation of a silicon carbide device capable of operation at high temperatures.