Device for supplying additional in-situ stress to film and measuring method for stress value thereof

Abstract

The invention discloses a device for supplying an additional in-situ stress to a film. The device comprises a dial indicator, a screw rod, a nut, a bracket, a bearing, a dial indicator fixing connecting rod, a metal blade fixing frame, an upper metal blade, a lower metal blade, a connecting rod, a clamp and a base, wherein the upper metal blade and the lower metal blade are fixed on an inner wall of the metal blade fixing frame; a clearance is arranged between the upper metal blade and the lower metal blade; one end of the connecting rod is fixed on the metal blade fixing frame; and the other end of the connecting rod is in contact with a measuring head of the dial indicator. A method for measuring a stress value by utilizing the device comprises the following steps: A) growing the film on a substrate; B) preparing an upper electrode of a film capacitor; C) fixing the film; D) applying a tensile stress; E) applying a pressure stress; F) measuring a position volume; G) measuring an effective length; H) measuring thickness; and I) measuring the stress value. When the device is utilized to supply the additional in-situ stress to the film, the 'idle running difference' is avoided and the measuring precision is increased.

Description

technical field [0001] The invention relates to the research field of stress effects on thin films, in particular to a device for providing external in-situ stress to thin films, and a method for measuring the stress value of thin films by using the device. Background technique [0002] Studying thin film properties plays an important role in the practical application of materials. Thin film properties include dielectric, ferroelectric, ferromagnetic, conductance, capacitance-voltage curve, etc. Different materials have different emphases. In the film preparation process, factors such as substrate mismatch, heat treatment, and integrated packaging of thin film devices will introduce MPa-level stress into the film. This stress has a great impact on the performance of the film in all aspects, and even affects the device. reliability and service life. Therefore, it is particularly important to study the change of film properties under stress. The ferromagnetic properties of ...

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Problems solved by technology

As far as we know, there are instruments that can test "in situ" ferromagnetic properties (remanent polarization, coercive field, fatigue) under tension and compression stress. inches), the sample sheet itself is used as the cover of a small vacuum chamber, and a vacuum pump or air source needs to be connected. By pumping or inflating the vacuum chamber, the center of the wafer sample is depressed or bulged upwards to reach the surface. For the purpose of applying compressive or tensile stress on the membrane surface, the specific force also needs to be calculated. The disadvantages of this measurement method are: complex structure, difficult operation, and large sample size

[0003] On the other hand, in our existing film stress testing device, the nut of the screw micrometer drives the screw and the movement of the metal knife edge to apply different stresses to the film. This method itself has large errors and is not enough. Intuitive and other defects, the main reason is: in operation, because the adjustment mechanism and the measuring unit of the film deformation are screw micrometers, and the reading of the rotating screw micrometer is generated by the rotation of the microtube driven by the adjustment nut, Sometimes the rotation of the micrometer cylinder has produced a change in reading, but the micrometer screw and the metal knife edge of the rotary screw micrometer have not yet moved, that is, no stress has been applied to the film, thus producing a "false stroke" phenomenon, resulting in " Poor air travel”, resulting in distorted readings

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