SIMULTANEOUS DETERMINATION OF LAYER THICKNESS AND SUBSTRATE TEMPERATURE DURING COATING

摘要

The invention describes a process and device for measuring temperature and layer thickness during coating by prior art methods in semiconductor manufacturing, plasma, ion and other dry-etching plants and in the production of optical coatings. The current results of layer thickness and temperature measurements may be used in process control. The interference phenomena in thermal substrate radiation on the growing layer continuously cause the emissivity ε to change during coating, thus preventing the use of pyrometric temperature measurement, which gives rise to particular problems in multi-layer systems in which the current emissivity depends on the thickness of all the layer, their optical constants, the temperature-dependence of the optical constant and the observation angle and wavelength. The present invention solves these fundamental problems by determining the reflectivity R of the wafer using a reflectometer. According to the law of the conservation of energy, for non-transparent substrates ε = 1 - R, and hence the current emissivity of the entire (multi-layer) system can be directly determined with the reflectometer. The temperature is measured by means of a given evaluation rule, while the thickness is found by comparing the reflectometer curve with the theoretical layer thickness dependence.