A new three dimensional IC fabrication technology, stacking thin film DUAL-CMOS layers

A novel 3-D IC has been developed in which electrical function blocks of thin-film dual-active-device-layer (DUAL) CMOS ICs are bonded cumulatively. In the DUAL-CMOS ICs, pMOSFETs are stacked on nMOSFETs by using a laser beam annealing technique. By mechano-chemical polishing, the IC substrates are thinned, and then joined together. Operation of function blocks such as an inverter and ring oscillator stacked in the 3-D IC is confirmed.<>