Method for altering mechanical and optical performance of thin film

Abstract

The invention discloses a method for changing the mechanical and optical properties of a thin film, which is characterized in that an amorphous silicon dioxide transition layer with compressive stress is arranged on a substrate, and then another layer with a compressive stress is arranged on the transition layer. Tensile-stressed amorphous silicon nitride film. This method overcomes the defects existing in the prior art, and improves the original steep stress gradient through the simple superposition of ordinary films with similar properties but opposite stresses, and can make the optical properties of the amorphous silicon nitride film lower by reducing the tensile stress of the film. The refractive index increases, and the hardness and Young's modulus of the film decrease accordingly, thereby effectively controlling the stress of a specific film, and preparing a low-stress silicon nitride film with low internal stress, which improves the working performance of the film and reduces It reduces the cost of raw materials and is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to the technical field of thin films of semiconductor devices, in particular to a method for changing the mechanical and optical properties of thin films. Background technique [0002] The magnitude of film stress directly affects the morphology of materials and devices, and in severe cases, it will cause warping and cracking of the film layer, and even cause serious damage to the device. Not only that, but thin film stress can have a huge impact on the material's properties. For example, the strained silicon technology widely used in semiconductor manufacturing in recent years is to use a certain degree of biaxial or uniaxial film stress (usually diastolic pressure) to greatly increase the mobility of electrons and holes in silicon. , resulting in an increase in device operating speed and a reduction in energy consumption (see M. Leong, B. Doris, J. Kedzierski, K. Rim, M. Yang, Science, 306, 2057-2060 (2004)). Therefore, thin f...

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Problems solved by technology

[0005] The Chinese patent CN 1964002A of R. Suanahayanan Yael et al. published on May 16, 2007 describes another method. This patent adds a layer in the middle of two layers of amorphous silicon nitride film The intermediate layer of different stresses is used to adjust the stress gradient of the film and prepare a stress-controlled silicon nitride film. This technical solution belongs to a new method, but its film structure and manufacturing process are complicated, the production cost is high, and it is not easy to apply in devices. in the mass production of

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