Study Of In-Ga-Zn-O Channel Based Thin-Film Transistor Memory Devices

As the development of and System on Panel (SoP) technology, pixel storage and blocks storage, Thin Film Transistor (TFT) will be integrated directly into SoP, so as to accomplish data storage and reduce power consumption. As a result, the non-violate memory based on TFT structure is becoming a hot topic. This paper has studied the IGZO channel based TFT memory. Based on these proposes. The content can be divided into the following three parts:Firstly, it has deposited amorphous IGZO film using magnetic sputtering process, and studied the properties of IGZO film under different sputtering condition. The resistivity, carrier concentration, carrier mobility and optical bandgap was proved to be affected by the sputtering condition of IGZO. It’s has been concluded that it’s the oxygen defect created by the sputter process that caused the change of IGZO material.Secondly, the IGZO channel based TFT memory with Al2O3/Pt nanocrystals (NCs)/Al2O3 insulator structure were fabricated. The Ion/Ioff ratio, subthreshold swing, effective electron mobility of the fabricated TFT memory devices were 106,0.388 V/dec, and 8.42 cm2/V·s respectively. A memory window of 5.63 V was achieved when the memory devices were programmed by a pulse voltage of 10 V/1 ms, and erased by the UV light of 100 mW/cm2/5 s. The memory window turned out to be 2.56 V after a retention time of 10 years. Besides it has analyzed why the devices cannot be erased by electricity effectively.Thirdly, the TFT memory devices with double Pt nanocrystals charge trapping layer were fabricated. When the memory devices were programmed by a pulse voltage of 10 V,1 ms, and erased by the UV light of 100 mW/cm2,5 s, the memory of was 7.3 V. And the memory window turned out to be 4.19 V after a retention time of 10 years. Finally, TFT memory with hetero-nanocrystals charge trapping layers was presented, and it was proved to be electrical erasable theoretically.