FLX 系列薄膜应力测量设备

FLX Series Precision Surface Stress Analysis

With thermal cycling and ambient auto-rotation models available, the Toho FLX Thin Film Stress Measurement Systems offer Industry Standard capabilities for mass production and research facilities that demand accurate stress measurements on various films and substrates. Incorporating KLA-Tencor’s patented “Dual Wavelength” technology, Toho FLX Series tools precisely determine and analyze surface stress caused by deposited thin films. In-situ stress measurements can be made from -65°C to 500°C at heating rates up to 25°C per minute (the cooling unit to -65°C is optional). An understanding of stress variations with temperature is essential for characterizing material properties such as stress relaxation, moisture evolution, and phase changes.

Equipment Overview and Principle

When a thin film is deposited on a substrate such as a silicon wafer, stress will be generated due to the differences in physical constants between the substrate and the thin film, leading to deformation of the substrate. Since the deformation caused by a uniformly deposited thin film manifests as substrate warpage, the stress can be calculated based on the amount of change in warpage (i.e., radius of curvature). This thin film stress measurement equipment measures the amount of change in the substrate's radius of curvature caused by the thin film attached to the substrate surface using the following method: as the calculation is performed based on the reflection angle of a laser scanned over the substrate, the amount of change in the radius of curvature is obtained by measuring the radii of curvature before and after the thin film deposition and calculating their difference. The thin film stress S is then calculated from the substrate's radius of curvature using the equation below.