Jiangsu Leadmicro Nano-Technology Co. Ltd, one of the leading suppliers of deposition and thermal processing tools, highlighted its latest tools applicable to TOPCon, HJT, XBC, and perovskite tandem solar cells at Intersolar Europe 2024. The company’s offerings encompass major process steps for TOPCon cell fabrication – rear and front-side passivation, and front-side emitter formation.
Speaking to TaiyangNews, the company focused on its latest ZR5000x2 series single-tube type PECVD system displayed at the show.
Rear side passivation
The ZR5000x2 series deposition tool is a ToxPoly all-in-one PECVD platform, in which all the steps, i.e., tunneling oxide as well as polysilicon deposition and in-situ doping, are accomplished using PECVD alone. This tool is capable of processing both mainstream wafer formats—M10 and G12. When processing the M10 size, the tool handles a batch size of 768 wafers per boat, reaching an hourly throughput of 6,800 wafers. The capacity drops to 616 pieces of wafers per boat when using G12 wafers, delivering a throughput of 5,280 wafers per hour. Given their high throughput, 3 units of the ZR5000x2 series PECVD tool are capable of handling a 1GW TOPCon production unit. The company emphasized that this all-in-one PECVD mass-production in a single tube reduces the process complexity, which is beneficial for high-efficiency cell making. Based on recent production data, this single-tube PECVD tool has achieved up to 743 mV open circuit voltage (Voc) for TOPCon cells.
The advantages of the latest tube-type model vis-à-vis its peers are cost optimization and a maintenance-free design. Leadmicro has introduced an innovative maintenance-free design, called ‘no-cooling electrode maintenance solution.’ As the name suggests, the maintenance of the electrode can be done without the need for the tube to cool down. In the traditional PECVD platform, electrode maintenance can last up to 25 hours, given the tube needs to be cooled before the electrode is taken out, followed by polishing and screening of the electrode, and then placed back into the tube. The tube needed to be heated up again and pre-coated before it could be reused. With the new process, the maintenance time has been reduced to only 5 hours, which leads to capacity utilization loss improvement by up to 87%. The company also added that the latest no-cooling maintenance-free design reduces the manpower requirement by 83%, making it best suited for the European market with high manpower costs.
Front side passivation & emitter formation
Alongside the PECVD solution, the company also displayed the KF-20000 series batch-type ALD tool, used for the TOPCon cell front side passivation with aluminum oxide (Al2O3) layer deposition. Moreover, the XH series high-temperature low-pressure thermal process system is promoted for all thermal needs of the TOPCon process—boron diffusion, annealing, and oxidation.