Method for testing the stress of side wall of field effect transistor

Abstract

The invention provides a method for testing the stress of side walls of a field effect transistor, belonging to the technical field of the field effect transistor preparation. The method comprises the following steps: steps are prepared on a substrate to form a grating structure; silicon nitride or silicon oxide is prepared on a grating structure, etched in the anisotropism way to form a side wall structure; a releasing area is defined, and the side wall is released to form a nano-beam structure; the material young modulus, material poisson's ratio and thickness of the nano-beam structure areused for respectively obtaining the axial stress in the nano-beam structure before releasing and the stress gradient along the thickness direction before the nano-beam releases by the measured curve curvature radius, the length before curve and the length after curve of the nano-beam structure, thus obtaining the stress of the side wall. The method solves the problem that the side wall structure stress in the strained silicon device research can not be tested, and is beneficial for increasing the design capability of an integrated circuit.

Description

technical field [0001] The invention relates to field effect transistor (MOSFET-Metal Oxide Silicon Field Effect Transistor, MOSFET for short) technology, in particular to a method for testing side wall stress of field effect transistor. Background technique [0002] Microelectronics technology has achieved rapid development driven by application requirements for decades. With the development of integrated circuit technology, the operating frequency and integration of devices have been greatly improved. However, with the continuous expansion of the scale of the circuit system, the performance requirements of the system for the device and the circuit are also getting higher and higher. Traditional materials and structural devices have great limitations in channel mobility. The speed of traditional bulk silicon material devices cannot be broken through, because the low mobility of silicon material itself greatly affects the speed of integrated circuit circuits. The strained ...

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Problems solved by technology

Therefore, when the mechanical characteristics of the sidewall are not understood, the introduction of the sidewall process will cause the threshold voltage of the transistors in each part of the chip to be different, which will bring a lot of trouble to the design.

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