Stress-Engineered SLIM-Cut of Ultra-Thin Silicon Using Saccharin-Modified Electroplated Ni Films

Stress-induced lift-off (SLIM-cut) is a kerf-free wafering route that can lower cost and thermal mass for wafer-level integration of low-power micro-heater gas sensors. However, prior SLIM-cut silicon often suffers from cracks and high residual stress, underscoring the need for precise stress control. Here we tune the internal stress of electroplated Ni by adjusting the saccharin concentration and activate the stress by furnace annealing to open a robust SLIM-cut window. Increasing saccharin drives the Ni film toward compressive stress; an optimum near zero internal stress (≈0 MPa) appears at ~8.0×10–7mol L–1, while a high-stress film (≈1.36 kgf mm–2≈ 13.3 MPa) exfoliates Ni without silicon. Under near-zero stress, we achieve uniform lift-off an ultra-thin silicon sheet with thickness ≈ 47 μm. X-ray diffraction shows Ni (111)/(200)/(220) peaks with saccharin-dependent crystallite size and peak shift, consistent with stress evolution. These results provide a controllable, wafer-compatible pathway to ultra-thin Si substrates that can reduce heater power and thermal time constants in metal-oxide gas sensors.