Temporary bonding material (TBM) enabled collective die-to-wafer (CoD2W) stacking requires the thermal budget to be well below 250 °C. This is incompatible with the standard process of record (POR) SiCN dielectric deposition temperature. In this work, we present a low-leakage and reliable SiCN material which is deposited at a lower temperature suitable for this application. The conduction mechanism and time dependent dielectric breakdown (TDDB) of LT SiCN dielectric layers with different compositions were investigated on a designed P-cap structure. Our studies indicate LT SiCN outperforms the POR SiCN by a significant margin. This improvement in the electrical characteristics has a good correlation to material composition. The optimized LT SiCN has a good potential to be applied to D2W and W2W processes to improve process compatibility.