The vertical integration of crystalline NMOS and amorphous orientational edge detector

The integration of the amorphous silicon (a-Si:H) orientational edge detector on top of the crystalline silicon metal-oxide-semiconductor (MOS) transistor has been achieved. The edge detector is an effective input device for pattern recognition in which only the skeleton of the object will be extracted, while the underlying MOSFET can amplify the response of the edge detector and perform further analysis. This integration can be viewed as a key step in combining crystalline silicon readout circuit and amorphous silicon edge detector to form three-dimensional architecture. It is a promising technique for future application in neural image sensors