Effects of Wafer Backside Emissivity Variation and System Control for Low Temperature Applications

1989 ◽  
Vol 146 ◽  
Author(s):  
Jay J. Pelletier ◽  
Thomsa E. Winter
Keyword(s):  
Low Temperature ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Nonlinear Effects ◽  
Processing Technology ◽  
System Control ◽  
Wafer Temperature ◽  
Lamp Current ◽  
Current Monitoring ◽  
Temperature Applications

ABSTRACTRapid thermal processing technology is being investigated for many uses such as shallow junction diffusion and implant annealing. Most of these processes are done at temperatures above 700 C. It is desirable to use the rapid thermal processor for some low temperature applications such as hillock reduction because of the systems ability to heat up and cool down almost instantaneously as compared to conventional furnaces. Machine control for low temperature processing is more difficult than high temperature processing dur to the optical pyrometers inability to perform at its lower limit. Well documented nonlinear effects of wafer backside emissivity over a temperature range of 400C to 600C will also contribute to wafer to wafer temperature instability. In order to fully utilize the advantages of rapid thermal processing technology, it is imperative that the RTPs performance and repeatability at low temperatures be understood.This paper will discuss the effect of wafer to wafer backside emissivity differences on wafer temperature for low temperature applications. Typical wafer to wafer backside emissivity variation is presented as well as the measurement error of the Peak “ACE” system. “ACE” (Automatic Compensation for Emissivity) can be used to correct for emissivity differences from wafer to wafer.Effect of improper emissivity selection on actual wafer temperature is presented. Also actual wafer temperature sensitivity to changes in programmed temperature with constant, uncompensated emissivity is demonstrated.Lamp current monitoring is discussed with supporting data to show the ability of it to be used as a day to day monitor of system performance. Also, The effects of lamp problems associated with idle current.

Low temperature shallow junction formation using vacuum ultraviolet photons during rapid thermal processing

1997 ◽  
Vol 70 (13) ◽  
pp. 1700-1702 ◽  
Author(s):  
R. Singh ◽  
K. C. Cherukuri ◽  
L. Vedula ◽  
A. Rohatgi ◽  
S. Narayanan
Keyword(s):  
Low Temperature ◽  
Thermal Processing ◽  
Vacuum Ultraviolet ◽  
Rapid Thermal Processing ◽  
Shallow Junction ◽  
Junction Formation ◽  
Ultraviolet Photons

scholarly journals Simulation of silicon wafers heating during rapid thermal processing using “UBTO 1801” unit

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 79-86
Author(s):  
J. A. Solovjov ◽  
V. A. Pilipenko ◽  
V. P. Yakovlev
Keyword(s):  
Mathematical Model ◽  
Silicon Wafer ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Light Flux ◽  
Silicon Wafers ◽  
Wafer Surface ◽  
Constant Density ◽  
Wafer Temperature

The present work is devoted to determination of the dependence of the heating temperature of the silicon wafer on the lamps power and the heating time during rapid thermal processing using “UBTO 1801” unit by irradiating the wafer backside with an incoherent flow of constant density light. As a result, a mathematical model of silicon wafer temperature variation was developed on the basis of the equation of nonstationary thermal conductivity and known temperature dependencies of the thermophysical properties of silicon and the emissivity of aluminum and silver applied to the planar surface of the silicon wafer. For experimental determination of the numerical parameters of the mathematical model, silicon wafers were heated with light single pulse of constant power to the temperature of one of three phase transitions such as aluminum-silicon eutectic formation, aluminum melting and silver melting. The time of phase transition formation on the wafer surface during rapid thermal processing was fixed by pyrometric method. In accordance with the developed mathematical model, we determined the conversion coefficient of the lamps electric power to the light flux power density with the numerical value of 5.16∙10-3 cm-2 . Increasing the lamps power from 690 to 2740 W leads to an increase in the silicon wafer temperature during rapid thermal processing from 550°to 930°K, respectively. With that, the wafer temperature prediction error in compliance with developed mathematical model makes less than 2.3 %. The work results can be used when developing new procedures of rapid thermal processing for silicon wafers.

Difference between Wafer Temperature and Thermocouple Reading during rapid Thermal Processing

1998 ◽  
Vol 525 ◽  
Author(s):  
T. Borca-Tasciuc ◽  
D. A. Achimov ◽  
G. Chen
Keyword(s):  
Temperature Measurement ◽  
Thermophysical Properties ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Simple Analytical Model ◽  
Calibration Standard ◽  
Wafer Temperature ◽  
Thermocouple Reading ◽  
The Difference ◽  
Thermocouple Temperature

ABSTRACTThermocouples are often used as a calibration standard for rapid thermal processing. Although it has been recognized that the thermocouple temperature can be different from the wafer temperature, the magnitude of the temperature difference is difficult to quantify. In this work, we present a simple analytical model to demonstrate the difference between the thermocouple temperature and the true wafer temperature. The results show that a large difference can exist between the thermocouple and the wafer temperature. This is because the optical and thermophysical properties of the thermocouple and the glue material are different from those of the wafer. The model results show that temperature measurement becomes more accurate if fine diameter thermocouple wires with very low emissivity are used.

In-Situ Temperature Control for Rtp Via Thermal Expansion Measurement

1993 ◽  
Vol 303 ◽  
Author(s):  
Bruce Peuse ◽  
Allan Rosekrans
Keyword(s):  
Thermal Expansion ◽  
Temperature Control ◽  
Measurement Technique ◽  
Preliminary Data ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Processing System ◽  
Wafer Temperature ◽  
Thermal Expansion Measurement

ABSTRACTA new method of temperature control for rapid thermal processing of silicon wafers is presented whereby in-situ wafer temperature is determined by measurement of wafer thermal expansion via an optical micrometer mechanism. The expansion measurement technique and its implementation into a rapid thermal processing system for temperature control are described. Preliminary data show the wafer to wafer temperature repeatability to be 1% (3-σ) using this technique.

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