A bonded assembly includes a first semiconductor die that includes first semiconductor devices, and a first pad-level dielectric layer and embedding first bonding pads; and a second semiconductor die that includes second semiconductor devices, and a second pad-level dielectric layer embedding second bonding pads that includes a respective second pad base portion. Each of the first bonding pads includes a respective first pad base portion and a respective first metal alloy material portion having a higher coefficient of thermal expansion (CTE) than the respective first pad base portion. Each of the second bonding pads is bonded to a respective one of the first bonding pads.