Study On Silicon-based Memristive Film Materials And Its Laser Irradiation Effects

Silicon-based memristive film is a dielectric semiconductor film that is simple in process and compatible with CMOS technology,and has attracted much attention in the field of next-generation memory devices and artificial intelligence.So far,there are many types of memristors built on silicon-based memristive materials.However,the silicon-based memristive film mostly uses a-Si as the mother phase,and corresponding memristor performances are gradually deteriorated with time due to the severe Staeber-Wronski(S-W)effect.Therefore,it is necessary to introduce partial crystallization in the silicon-based memristive film to improve the structural stability of the film.In this paper,Ag(Al)doped amorphous silicon memristive film material(a-Si:Ag(Al))was prepared by magnetron sputtering method.The radiation was modified by femtosecond laser with different energies.Metallographic microscope,scanning electron microscopy,laser Raman spectroscopy,X-ray diffraction analyzer and visible-near-infrared spectroscopy were used to study the effects of metal content and femtosecond laser energy on the microstructure and photoelectric properties of memristive film materials.The main results achieved are as follows:(1)Both Ag and Al in the prepared a-Si:Ag(Al)film are distributed in a simple form in the amorphous network.The increase of Ag content will increase the short-range and medium-range disorder of the film,increase the spectral absorption rate of the film,decrease the spectral transmittance and resistivity;With the increase of the Al content,the medium-range order of the film increases and the resistivity reduces.(2)After being irradiated by femtosecond laser,Gaussian distribution of irradiation spot marks appear on the surface of the a-Si: Ag(Al)film.As the laser energy increases,the traces of the irradiated spot become more and more obvious.Whether it is a-Si or a-Si:Ag(Al)film,the crystallization rate of amorphous silicon from the center to the edge in the same spot gradually decreases and the silicon grain size gradually becomes smaller.Under the same energy density irradiation,as the metal content increases,the crystallization of the thin film will be gradually suppressed,and the size of the generated crystalline silicon particles will gradually decreases.Among them,Ag has a stronger inhibitory effect than Al;With the laser energy increases,the crystallization of amorphous silicon in the a-Si:Ag(Al)film increases,but the grain size of the silicondoes not significantly increase.(3)The effects of Ag and Al on the spectral properties of a-Si films are completely different.The a-Si:Ag film has lower resistivity,lower spectral transmittance,higher spectral absorptivity,weaker interference peaks of transmission spectrum and reflection spectrum than a-Si film.And the higher the Ag content,the more obvious the phenomenon;After femtosecond laser irradiation,the interference peaks in the spectral curves of the a-Si film and the a-Si:Ag film get weakened,and the resistivity lowers.The spectral curves of a-Si:Al film and a-Si film are not much different,but the former has lower resistivity than the latter;After femtosecond laser irradiation,the interference peaks of a-Si:Al film and a-Si film weaken,the resistivity decreases,and the higher the Al content,the stronger the interference peaks in the spectral curve of the film.As the laser energy increases,the reflectance of the a-Si:Ag(Al)film decreases,and the absorptivity and resistivity slightly increase.