Innovative Equipment for the Preparation of 150mm Multicrystalline Silicon: Final Report

Abstract:

<p>This project had two primary goals; the first to develop the next generation of multicrystalline silicon ingot growth system capable of producing ingots up to 90cm square and weighing up to 500kg. The second goal was to develop equipment which could be used to automate the ingot-to-block processes and to minimise the levels of manual handling required, especially for the heavier blocks of sizes 150mm and above.</p> <p>The crystal growth system operated successfully during growth trials and the quality of silicon produced met photovoltaic standard requirements. The testing of the growth system was undertaken through a series of growth trials, each designed to progressively test the system's capabilities. The first trials tested the functionality of the graphite furnace, power supply and coil arrangements; only minor optimisation was required to obtain efficient coupling. Heating trials were the undertaken to prove the operation and robustness of the furnace design. The susceptors and insulation showed no damage or problems at the completion of the tests. Work was undertaken in parallel to assess the effectiveness of a pyrometer for both temperature control and monitoring but the repeatability between runs in the existing set-up was inadequate to allow it be used in production and thermocouples were retained.</p> <p>The project has successfully develop the crystal growth system and block process line as set out in the initial proposal. The use of 3D CAD and finite element analysis (FEA) has been successfully implemented on this project and has greatly reduced the time and costs associated with the development of operation systems by identifying and resolving potential problems before components were put into manufacture.</p> This report contains and executive summary, and is divided into the following sections: <ol> <li>Introduction</li> <li>Project Objectives</li> <li>90cm Multicrystalline Silicon Growth System</li> <li>Block Process Line Equipment</li> <li>Acknowledgements</li> </ol>

Author(s):

Merrick, P.