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.

Manufacture of semiconductor device

Abstract: PURPOSE:To make it possible to form an insulating film having a superior buried flatness and to contrive to improve the yield of the manufacture of an integrated circuit device because the insulating film having the superior flatness can be formed by a process only of one time by a method wherein a deposited film in a fluid state is vapor-phase grown on the main surface of a semiconductor substrate at a substrate temperature equal to an higher than the glass transition temperature of the deposited film. CONSTITUTION:In the manufacturing process of a semiconductor device, wherein a deposited film 204 is formed for flattening a step of the main surface of a semiconductor substrate, the film 204 in a fluid state is vapor-phase grown on the main surface of the substrate using a substrate temperature of the glass transition temperature or higher of the film 204. For example, an insulating film 202 is formed on a single crystal silicon substrate 201 with an semiconductor element formed thereon and moreover, polycrystalline silicon wirings 203 are formed. Then, a vapor growth of a fluid BPSG film 204 is performed at a substrate temperature of 900 deg.C, at a pressure of 0.6 Torr, at the flow rate of 120SCCM of SiH4 gas, at the flow rate of 2 slm of N2O gas, at the flow rate of 10SCCM of PH3 gas and the flow rate of 10SCCM of B2H6 gas. Thereby, the formed film 204 becomes one having a flatness superior that of a conventional film obtainable by performing two processes of film formation and reflow.

Simple integral screenprinting process for selective emitter polycrystalline silicon solar cells

Abstract: This letter describes a new simple fabrication process, developed recently for ‘‘blue response’’ improvement in low‐cost polycrystalline silicon solar cells. A selective emitter is created by heavily doping the emitter, followed by a wet etching‐back of the cell area between the fingers. An improvement up to 17 mV in Voc, 1.5 mA/cm2 in Jsc, and 1% (absolute value) in η is obtained. Effective phosphorus gettering, self‐alignment, and application in a low‐cost full screenprinting technology are the main advantages of the proposed process.

Role of the chamber wall in low‐pressure high‐density etching plasmas

Abstract: Ultraviolet‐adsorption spectroscopy has been used to examine how the chamber wall affects the concentration of gas‐phase reactants in high‐density etching plasmas. This technique was employed to detect CF2 in an inductively coupled discharge used for the selective etching of silicon dioxide relative to silicon nitride and polycrystalline silicon (polysilicon) films. In plasmas containing C2F6 and CF4, the concentration of CF2 depends strongly on the applied power and operating pressure as well as the amount of polymer on the walls of the chamber. Changes in the conditioning of the chamber during the etch process cause significant variations in the concentration of CF2 in the discharge. The selectivity of etching SiO2 relative to Si3N4 films closely follows the concentration of CF2 under a variety of plasma operating conditions. The ability to measure a fundamental plasma characteristic that reflects the level of conditioning of the chamber is an important step in the real‐time monitoring of a reactor parameter that currently can only be determined from postprocess measurements.

Effect of grain size and dislocation density on the performance of thin film polycrystalline silicon solar cells

Abstract: Three kinds of important properties of the solar cell were calculated: short-circuit current density, open-circuit voltage, and conversion efficiency. Two equations which show the relationship between the minority-carrier diffusion length and the grain size or the etch pit density were used for the calculation. The dependence of the properties on the cell thickness were estimated as a function of grain size and etch-pit density. The effect of the internal reflectance with varying minority-carrier diffusion length was also examined. The results show that thin film polycrystalline silicon solar cells have the potential to attain an efficiency of 17% even at a film thickness of 2 μm if the grain size is bigger than 10 μm and the etch-pit density of less than 1×106 cm−2. The principal requirement is to achieve efficient light trapping.