Research On Measurement Method Of Silicon Interface Field Based On Linear Electro-optic Effect

Silicon material is currently a material that plays an important role in integrated devices and large-scale integrated circuits.Because of its rich raw material,low price,and relatively stable physical properties,its utilization rate is getting higher and higher.Therefore,the detection method of silicon material and its device performance has also become an important research content.On the other hand,it was found that the use of a strong interaction field can destroy its symmetry and cause it to produce a linear electro-optical effect.This discovery has been widely studied and applied in the field of optical communication.In this paper,we will use the electro-optic effect of silicon and the electric field and the corresponding relationship between the stress field,based on the linear electro-optic effect,proposes an electro-optic detection scheme for the size and distribution of the electric field and stress on the silicon material,and its experimental verification.The specific conclusions are as follows:(1)Theoretical calculations were used to obtain the correspondence between the linear electro-optic effect and the electric field at the surface and interface of the silicon material.Using this relationship,the size and distribution of the built-in electric field and the applied DC electric field were calculated by measuring the electro-optic signal in the space charge area at the silicon interface.Compared with the theoretical value of the electric field distribution in the Schottky barrier,it was found that the proposed method was in good agreement with the theory and has practicality.It has proposed a new method for measuring the electric field distribution of silicon devices.(2)The correspondence relationship between the linear electro-optic effect and the stress field is summarized theoretically,and the uniaxial stress was continuously applied at the center point of the silicon material using a self-made stress application device.The electro-optical signal of the strained silicon material was measured to verify the theoretical analysis and the experimental phase.(3)On this basis,this method was used to measure the distribution and magnitude of the stress field at the Si/SiO2 interface with an oxide thickness of 4 nm.The experimental results showed that the Si stress at the Si/SiO2 interface is approximately1.876?10~7 Pa.In short,this paper systematically studies the electro-optical properties of the silicon interface and the surface through the above two optical experiments.Here,we not only proposed a measurement method based on the linear electro-optical effect for the distribution of electric fields in silicon materials,but also proposed a method for measuring the stress magnitude and distribution at the interface of silicon materials based on the linear electro-optical effect.These conclusions are rarely found in the literature.Some conclusions drawn,or analysis and measurement of the interface state of silicon-based devices,and the application of silicon materials have been helpful.It has certain innovation and practicality.