Title:	LPCVD In-Situ n-Type Doped Polysilicon Process Throughput Optimization and Implementation into an Industrial Solar Cell Process Flow
Author(s):	R.C.G. Naber, B.W.H. van de Loo, J.R.M. Luchies
Keywords:	Contact, Passivation, n-Type, Silicon (Si) Solar Cells
Topic:	Silicon Materials and Cells
Subtopic:	Homojunction Solar Cells
Event:	36th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2BO.3.2
Pages:	180 - 183
ISBN:	3-936338-60-4
Paper DOI:	10.4229/EUPVSEC20192019-2BO.3.2
Price:	0,00 EUR
Document(s):	paper, presentation

Abstract/Summary:

---

We present our results on obtaining a higher throughput for an LPCVD polysilicon process that incorporates both in-situ tunnel oxide formation and in-situ n-type doping and demonstrate the application of the layers with lifetime and solar cell experiments. In-situ n-type doping can enable a simplification of solar cell production processes but the process throughput can be limited by layer thickness and doping uniformity issues. In this work we demonstrate that it is possible to enhance the deposition rate without compromising the uniformity by controlling the process conditions in a precise way. Layers made with such an enhanced throughput have a high dopant concentration of ~2E20 cm-3 that is suitable for contacting and they show an excellent passivation performance on lifetime samples with an average J0 down to 2.3 fA·cm-2 per side. We also developed a TOPCon solar cell process flow that incorporates the developed in-situ doped polysilicon process. Our best result so far was a VOC and efficiency of 685 mV and 22.2%, respectively, as obtained by fire-through contact metallization with a 5-busbar design.