Preparation And Properties Study Of The SnO And Mn-SnO Thin Films

With the rapid development of modern information technology, the large scale integrated circuits get smaller, and gradually achieve nanoscale. Traditional electronic technology can’t meet the requirements of ultra-high speed and ultra-wide band in development of the information technology. Researchers have begun to envisage preparing a kind of semiconductor material, which has both electrical characteristics and magnetic properties. This material also can process and store information by the electron spin and charge simultaneously. Much more attention has been attracted by the diluted magnetic semiconductors for combination of charge and spin properties of electrons. The spintronics involves in many kinds of fields. To achieve the goal of spintronics, a spin-polarized current is injected into the semiconductor material to achieve the information processing function. So the key problem is that a diluted magnetic semiconductor material with high Curie temperature and high spin polarization can be prepared.At present, the main preparation method of diluted magnetic semiconductors is that doping the transition metal elements into the semiconductor materials. For example, great progress has been made in Mn-doped GaAs, However, due to its low ferromagnetic Curie temperature, the application is limited. Therefore, many researchers focus on looking for diluted magnetic semiconductors with room temperature ferromagnetism. In our works, we found that the existing Si-based P-type semiconductors fail to meet the pursuit of diluted magnetic semiconductor properties. So, searching for a high stability and high mobility P-type semiconductor has become a popular direction of microelectronics. SnO, a P-type semiconductor material, has attracted wide attention. The mobility of SnO is higher than general P-type semiconductor material. Compared with the P-type ZnO-based semiconductor material, the stability of SnO behaves well. High-quality SnO films have been prepared and their physical properties have been studied. Moreover, we have also prepared a high-quality Mn-doped SnO diluted magnetic semiconductor thin film and investigated their physical properties. The works are summarized as follows:1. SnO films have been prepared with SnO target at different substrate temperature, prepared SnO films with Sn target at different partial pressure of oxygen. The substrates of films are all YSZ. We prepared SnO films on ITO (111) epitaxial indirection with SnO target, and studied the resistance properties of SnO in the YSZ-ITO-SnO-Al heterostructure. We found that SnO can be used not only as a P-type semiconductor material but also as a resistive switching.2. A series of Mn-SnO films have been prepared with different Mn composition, and their magnetic and optical properties have been measured. It was found that the Bound Magnetic Polaron model can well explain the phenomenon that the room temperature ferromagnetism decreases and then increases with the increase of doping Mn. The absorption edge has a blue shift after the first red shift by spectrum measurement. So the width of the band gap can be adjusted by controlling the doping amount of Mn. The Mn-doped SnO film, a dilute magnetic semiconductor materials, will have a good prospect in spintronics devices.