Effective anisotropic etching of silicon wafers in temperature gradients - variation of surface topography and reflectivity with a specially designed apparatus

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F17%3A63518097" target="_blank" >RIV/70883521:28610/17:63518097 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Effective anisotropic etching of silicon wafers in temperature gradients - variation of surface topography and reflectivity with a specially designed apparatus

Original language description

The minimization of energy losses on silicon wafers intended for solar panel assembly is one of the fundamental tasks in production of efficient power units. Decreasing the reflection of electromagnetic radiation from silicon surfaces can be achieved by thin layer antireflective coating and/or surface texturing. Anisotropic surface texturing process of monocrystalline (100, 110 and 111) or polycrystalline silicon often utilizes acidic or alkaline solutions with various additives. Also quite complicated machinery with many moving parts is used. The aim of the study was to develop a special apparatus, allowing avoiding possible contamination of wafers during the etching process by using etching solution containing only potassium hydroxide and isopropyl alcohol and employing the so-called Bénard-Marangoni thermocapillar instability, where the main driving force for spontaneous self-organized liquid movement is the temperature difference between the bottom layer of the liquid and its open surface. Opposed to the situation where the etching medium and reaction by-product move randomly in the surface vicinity, the self-organized flow initiated by the temperature difference makes the etching solution to quickly change over the surface and no accumulation of reaction product at the surface occurs, thus not slowing the etching rate. Also, as the apparatus does not contain any moving parts, so the sources of possible contamination are greatly reduced, this is among the key aspects monitored in the silicon wafer processing industry. It was further proved, that the silicon wafer surfaces (orientation 100) etched in the apparatus exhibit significantly lower reflectivity in the visible spectrum compared to the original samples. The apparatus thus may allow for more rapid, efficient and ecological process of silicon wafer surface topography modification.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů