Controlling Physical and Electrical Properties of Polysilicon

Polysilicon is widely used in semiconductor technologies for forming gate electrodes in MOS devices, precision electrical resistors, and waveguides in optical devices. The properties of deposited polysilicon are generally predictable and stable, allowing us to control only the height and width of polysilicon structures using inline measurements to ensure the desired electrical properties. However, in some cases, height and width measurements alone are not sufficient to ensure the proper electrical properties, particularly electrical resistance. To achieve the target electrical resistance in polysilicon with specific physical dimension, it is crucial to control the grain size. We demonstrate a simple in-line inspection method for grain size and propose an effective control method for mass production, utilizing Auto Machine Learning(AutoML)