200 mm wafer level processing of QDot™ quantum dot n-type ink

Southampton, 12.02.2024 — Quantum Solutions is pleased to announce the successful demonstration of wafer-level deposition of QDot™ PbS quantum dot n-type ink on a 200 mm silicon ROIC (read-out integrated circuit) wafer. This groundbreaking work highlights the feasibility of producing SWIR (short-wave infrared) image sensors with high throughput on 200 mm wafer platforms, essential for large-scale manufacturing of sensors.

The QDot PbS n-type ink was efficiently introduced into the 200 mm imec FAB for a single-step spin-coating process. The single-step deposition of the ink was executed seamlessly over the 200mm wafer, achieving a thickness range of 50-100 nm depending on the spin-coating speed parameters. The resulting thin films were smooth and free of noticeable defects, with less than 4% thickness variation observed across the 200 mm wafer:

Additionally, multistep coating of thicker films up to 200-300 nm was verified. Furthermore, we successfully implemented Edge Bead Removal (EBR) technique on the wafer:

Quantum Solutions’ QDot™ PbS quantum dot n-type ink (n-ink) is specifically designed for manufacturing high-efficiency SWIR (short-wave infrared) photodiodes and image sensors. This ink streamlines the solution-processing fabrication flow of quantum dot SWIR sensors by eliminating the need for complex solid ligand exchange procedures. The ink also facilitates cost-effective production because it requires a smaller volume for coating large wafers, comparable to multistep solid ligand exchange process. This makes it a practical choice for scaling up production of SWIR photodiodes and image sensors. For more details, please contact us at info@quantum-solutions.com.