Temperature Measurement Issues in Rapid Thermal Processing

1997 ◽  
Vol 470 ◽  
Author(s):  
D. P. DeWitt ◽  
F. Y. Sorrell ◽  
J. K. Elliott

ABSTRACTReliable radiometrie temperature measurement has been a major challenge in making rapid thermal processing (RTP) more widely accepted. In order to meet road map requirements involving temperature uncertainty, uniformity and control, new techniques must be demonstrated and/or existing measurement methods must be substantially improved. Critical aspects of radiometrie methods for temperature measurement are centered about the topics: radiative and optical properties of the wafers including layered systems, surface roughness effects, and reflected irradiation from lamp banks and chamber walls. The systematic method for inferring temperature is rooted in the measurement equation which relates the radiometer output to the exitent spectral radiance from the target which reaches the detector and prescribes the roles that emissivity variability and stray radiation have on the result. An overview is provided on the knowledge base for optical and thermal radiative properties. Methods for reducing emissivity and stray radiation effects are summarized. Calibration procedures necessary to assure that the in-chamber or local temperature scale is traceable to the International Temperature Scale (ITS-90) are discussed. The issues which can impact improved temperature measurement practice are summarized.

1995 ◽  
Vol 387 ◽  
Author(s):  
Peter Y. Wong ◽  
Ioannis N. Miaoulis ◽  
Cynthia G. Madras

AbstractTemperature measurements and processing uniformity continue to be major issues in Rapid Thermal Processing. Spatial and temporal variations in thermal radiative properties of the wafer surface are sources of non-uniformities and dynamic variations. These effects are due to changes in spectral distribution (wafer or heat source), oxidation, epitaxy, silicidation, and other microstructural transformations. Additionally, other variations are induced by the underlying (before processing) and developing (during processing) patterns on the wafer. Numerical simulations of Co silicidation that account for these factors are conducted to determine the radiative properties, heat transfer dynamics, and resultant processing uniformity.


1996 ◽  
Vol 429 ◽  
Author(s):  
P. J. Timans

AbstractRapid thermal processing (RTP) has become a key technology in the fabrication of advanced semiconductor devices. As RTP becomes the accepted technique for an increasingly wide range of processes in device fabrication, the understanding of the basic physics of radiation heat transfer in RTP systems is also being extended rapidly. This paper illustrates the use of optical models for prediction of the thermal radiative properties of semiconductor wafers. Such calculations can be used to address many of the key issues of interest in RTP, including questions concerning temperature measurement and process repeatability.


1995 ◽  
Vol 389 ◽  
Author(s):  
Peter Y. Wong ◽  
Ioannis N. Miaoulis ◽  
Cynthia G. Madras

ABSTRACTTemperature measurements and processing uniformity continue to be major issues in Rapid Thermal Processing. Spatial and temporal variations in thermal radiative properties of the wafer surface are sources of non-uniformities and dynamic variations. These effects are due to changes in spectral distribution (wafer or heat source), oxidation, epitaxy, silicidation, and other microstructural transformations. Additionally, other variations are induced by the underlying (before processing) and developing (during processing) patterns on the wafer. Numerical simulations of Co silicidation that account for these factors are conducted to determine the radiative properties, heat transfer dynamics, and resultant processing uniformity.


1994 ◽  
Vol 342 ◽  
Author(s):  
Peter Y. Wong ◽  
Ioannis N. Miaoulis

ABSTRACTMicroscale radiation effects are responsible for the dependence of absorption and temperature distributions on the geometry of the layering structures and the spectral characteristics of the heat source. The effect of patterned wafers, which may contain several different structures and materials, on the wafer absorption characteristics are investigated for rapid thermal processing. A numerical model to determine the thermal radiative absorptivity of the wafer for different structures and materials is presented for different heating conditions. The resulting transient effects are determined numerically for different rapid thermal processes. The changes in radiative properties for rapid thermal annealing and chemical vapor deposition are investigated for patterned wafers.


2000 ◽  
Author(s):  
Y. H. Zhou ◽  
Y. J. Shen ◽  
Z. M. Zhang ◽  
B. K. Tsai ◽  
D. P. DeWitt

Abstract This work employs a Monte Carlo method to study the radiative process in a rapid thermal processing (RTP) furnace. A “true” effective emissivity, accounting for the directional optical properties, is defined and predicted in order to determine the wafer temperature from the measured spectral radiance temperature using light-pipe radiation thermometry. The true effective emissivity is the same as the hemispherical effective emissivity for diffuse wafers, in which case the Monte Carlo model gives the same results as the net-radiation method. Deviations exist between the hemispherical effective emissivity and the true effective emissivity for specular wafers because the effective emissivity is directional dependent. This research will help reduce the uncertainty in the temperature measurement for RTP furnaces to meet the future requirements for integrated circuit manufacturing.


1989 ◽  
Vol 55 (9) ◽  
pp. 840-842 ◽  
Author(s):  
G. Q. Lo ◽  
D. K. Shih ◽  
W. C. Ting ◽  
D. L. Kwong

1993 ◽  
Vol 303 ◽  
Author(s):  
Peter Y. Wong ◽  
Christopher K. Hess ◽  
Ioannis N. Miaoulis

ABSTRACTThe individual film thicknesses of multilayered structures processed by rapid thermal processing are of the same order as the wavelengths of the incident radiation. This induces optical interference effects which are responsible for the strong dependency of surface reflectivity, emissivity, and temperature distributions on the geometry of the layering structures, presence of patterns, and thickness of the films. A two-dimensional, finitedifference numerical model has been developed to investigate this microscale radiation phenomena and identify the critical processing parameters which affect rapid thermal processing of multilayer thin films. The uniformity of temperature distributions throughout the wafer during rapid thermal processing is directly affected by incident heater configurations, ramping conditions, wafer-edge effects, and thin-film layering structure. Results from the numerical model for various film structures are presented for chemical vapor deposition of polycrystalline silicon over oxide films on substrate. A novel technique using an edge-enhanced wafer which has a different film structure near its edge is presented as a control over the transient temperature distribution.


1997 ◽  
Vol 82 (2) ◽  
pp. 830-835 ◽  
Author(s):  
G. Chen ◽  
T. Borca-Tasciuc ◽  
R. B. Fair

1998 ◽  
Vol 525 ◽  
Author(s):  
A. R. Abramson ◽  
H. Tadal ◽  
P. Nieva ◽  
P. Zavracky ◽  
I. N. Miaoulis ◽  
...  

ABSTRACTThe radiative properties of a silicon wafer undergoing Rapid Thermal Processing (RTP) are contingent upon the doping level of the silicon substrate and film structure on the wafer, and fluctuate drastically with temperature and wavelength. For a lightly doped substrate, partial transparency effects must be considered that significantly affect absorption characteristics. Band gap, free carrier, and lattice absorption are the dominant absorption mechanisms and either individually or in concert have considerable effect on the overall absorption coefficient of the silicon wafer. At high doping levels, partial transparency effects dissipate, and the substrate may be considered optically thick. A numerical model has been developed to examine partial transparency effects, and to compare lightly doped (partially transparent) and heavily doped (opaque) silicon wafers with a multilayer film structure during RTP.


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