OPTICAL MEASUREMENT OF A HIGHLY ABSORBING FILM LAYER OVER HIGHLY REFLECTIVE FILM STACKS

• Main Authors: KRISHNAN SHANKAR, YGARTUA CARLOS L
• Format: Patent
• Language: Chinese; English
• Published: 19.05.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Apparatus and methods for performing optically based film thickness measurements of highly absorbing films (e.g., high-K dielectric films) with improved measurement sensitivity are described herein. Ahighly absorbing film layer is fabricated on top of a highly reflective film stack. The highly reflective film stack includes one or more nominally identical sets of multiple layers of different, optically contrasting materials. The highly reflective film stack gives rise to optical resonance in particular wavelength ranges. The high reflectance at the interface of the highly absorbing film layerand the highly reflective film stack increases measured light intensity and measurement sensitivity. The thickness and optical dispersion of the different material layers of the highly reflective film stack are selected to induce optical resonance in a desired wavelength range. The desired wavelength range is selected to minimize absorption by the highly absorbing film under measurement. 本文描述了用于以改进的测量灵敏度来对高吸收膜(例如，高K介电膜)执行