Light Wavelength Effects on Charge Trapping and Detrapping of AlO_x Embedded ZrHfO High-K Stack

Abstract

The ZrHfO/AlO x /ZrHfO high- k gate dielectric memory capacitors on the p -type Si wafer have been fabricated using the one pumpdown sputtering process followed by rapid thermal annealing. The memory functions were mainly based on holes trapping at the AlO x site and AlO x /ZrHfO interface layer. The hole generation, transfer and storage in the dielectric structure was influenced by light exposure, e.g., the device retained fewer holes with the increase of the wavelength of the light. Under the light exposure, the leakage current decreased in the negative voltage range but increased in the large positive voltage range. The light exposure effect is important for practical applications of the device.