Comprehensive RTP modeling and simulation including thermal stress analysis and feature size optical effects

Abstract

A comprehensive simulation capability to describe RTP related issues has been developed. The simulator describes: 1) The radiative heat transfer in 3D with cylindric symmetry by combined zonal-Monte-Carlo method for arbitrary geometry and for various boundary conditions. The spectrum of tungstenhalogen lamp is modeled realistically and the software allows for analysis of multivariable independent lamp control; 2) Conductive heat transfer in the patterned wafer as a function of patterns (3D representation -crucial for stress analysis) and in the chamber walls (important for temperature uniformity from run to run); 3) 3D wafer warpage and thermal stress analysis of the wafer treated as a laminated plate; 4) Electromagnetic wave interaction with the object of a size comparable to the wave length of radiation for multi-layered nonplanar structures including steps and trenches.; 5 ) Evaluation of emissivity of the wafer with deposited films for optical pyrometry. The software has been applied to various situations of which selected subsequent examples demonstrate its capability.A. Radiative Heat Transfer 3D radiative heat transfer in an RTP chamber with arbitrary shape of the chamber geometry, wafer (edge shape), reflecting shields, etc. (Fig.1) has been implemented. A hybrid zonal-MC numerical method is used; specular multiple reflections exchange factors and diffusive reflections view factors are employed. The exchange factors are updated at each time step to account for changing optical properties as a function of wave length, temperature and substrate doping. The model takes into account realistic spectral and temperature dependences of the optical properties of the wafer and chamber walls which may be opaque or semitransparent. In Fig.2 temperature nonuniformity as a function of radial position on the wafer for different time steps for two lamp powerings is shown. Chamber geometry and lamps configuration shown in Fig.1 were used. In both cases steady temperature of the center was 1023 K. During ramp-up, when thermal radiation from the wafer is considerably smaller than from the lamps, the center is colder than the edge due to more intense radiative heating of the edge. As the wafer is heated radiative losses from the wafer edge make the edge cooler than the center (steady state). The temperature has been studied for various lamp, shield ( Fig. 1) and wafer coating configurations. Diffusive reflections are more effective for wafer heating than specular reflections. This fact can be used in designing the chamber surfaces. However, correct data for the angular dependence of the diffusively reflective surfaces are needed. 0 0 Lamparrays 0 0 Qartz window Wafer Fig.1. Schematic sketch of cylindric RTP chamber.

Simulation of infrared rapid surface heating for injection molding

“…The short wavelength ($1 lm) halogen lamps are used as the infrared source. The silicon substrate is insulated by quartz pillars and the temperature of silicon substrate can be raised from 300 K to 1300 K in 10 s. Some researchers have studied the temperature control of the RTPCVD system [8,9]. Habuka et al [10,11] have used a direct approach using the three-dimensional ray-tracing simulation (DARTS model) to evaluate the thermal condition in a RTP system.…”

Experimental investigation of infrared rapid surface heating for injection molding

“…Because of vacuum environment in the CVD chamber, radiation is a more efficient way to heat the silicon substrates rapidly. Some researchers have studied the temperature control of the RTPCVD system 9–12. Short wavelength (∼ 1 μm) halogen lamps are used as the infrared source.…”

Geometry Influence of Reflectors for Infrared Rapid Heating on Micro-Injection Molding

“…The silicon substrate is insulated by quartz pillars and the temperature of silicon substrate can be raised form 300K to 1300K in 10 seconds. Some researchers have studied the temperature control of the RTPCVD system [5,6]. A direct approach using the three-dimensional ray-tracing simulation (DARTS model) to evaluate the thermal condition in a RTP system was developed [7,8].…”