Microscale Radiation Effects in Multilayer Thin-Film Structures During Rapid Thermal Processing

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.

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.


1993 ◽  
Vol 303 ◽  
Author(s):  
E. Campo ◽  
J.J. Pedroviejo ◽  
E. Scheid ◽  
D. Bielle-Daspet ◽  
A. Yahia Messaoud ◽  
...  

ABSTRACTIn this work, we studied the rapid crystallization and the rapid tbermal oxidation of amorphous silicon films deposited at 465°C by low-pressure chemical vapor deposition (LPCVD) from disilane. The crystallization is well-controlled and the thermal bugdet is reduced compared to conventional processes. Results concerning the electrical and structural characteristics of poly-Si thin film transistors (TF7) are given. Furthermore, we obtained after plasma hydrogenation better mobilities in the case of rapid thermal processing (RTP) (μp-61 cm2/V.s, VT−8.3 V, subtbreshold slope−-0.8 V/decade, ION/IOFF− 1. 106 for p-type and μn-80 cm2/V.s, VT−3. 7 V, subthreshold slope−1.4 VWdecade, ION/IOFF−5.104 for n-type) compared to conventional processing performed at 600°C. The mobilities are improved by a factor of 2 to 3 despite the smaller grain size in the silicon films. We also showed a correlation between the optical absorption coefficient k (at 405nm) and the mobility wbicb appears not only dependent upon, the grain size but also upon the grain quality (grain boundaries and defects inside the grain).This study shows that the structural and electrical properties of thin-films and oxides fabricated by RTP are at least as good as those obtained by conventional techniques.


2002 ◽  
Vol 745 ◽  
Author(s):  
Erik Haralson ◽  
Tobias Jarmar ◽  
Johan Seger ◽  
Henry H. Radamson ◽  
Shi-Li Zhang ◽  
...  

ABSTRACTThe reactions of Ni with polycrystalline Si, Si0.82Ge0.18 and Si0.818Ge0.18C0.002 films in two different configurations during rapid thermal processing were studied. For the usually studied planar configuration with 20 nm thick Ni on 130–290 nm thick Si1-x-yGexCy, NiSi1-xGex(C) forms at 450°C on either Si0.82Ge0.18 or Si0.818Ge0.18C0.002, comparable to NiSi formed on Si. However, the agglomeration of NiSi1-xGex(C) on Si0.818Ge0.18C0.002 occurs at 625°C, about 50°C higher than that of NiSi1-xGex on Si0.82Ge0.18. For thin-film lateral diffusion couples, a 200-nm thick Ni film was in contact with 80–130 nm thick Si1-x-yGexCy through 1–10 μm sized contact openings in a 170 nm thick SiO2 isolation. While the Ni3Si phase was formed for both the Si0.82Ge0.18 and Si0.818Ge0.18C0.002 samples, the presence of 0.2 at.% C caused a slightly slower lateral growth.


2012 ◽  
Vol 15 (4) ◽  
pp. 269-275 ◽  
Author(s):  
Marcus Hopfeld ◽  
Rolf Grieseler ◽  
Thomas Kups ◽  
Marcus Wilke ◽  
Peter Schaaf

2006 ◽  
Vol 129 (3) ◽  
pp. 323-326
Author(s):  
Sachin S. Kulkarni ◽  
Jyoti S. Shirolikar ◽  
Neelkanth G. Dhere

Rapid thermal processing (RTP) provides a way to rapidly heat substrates to an elevated temperature to perform relatively short duration processes, typically less than 2–3min long. RTP can be utilized to minimize the process cycle time without compromising process uniformity, thus eliminating a bottleneck in CuIn1−xGaxSe2−ySy (CIGSS) module fabrication. Some approaches have been able to realize solar cells with conversion efficiencies close or equal to those for conventionally processed solar cells with similar device structures. A RTP reactor for preparation of CIGSS thin films on 10cm×10cm substrates has been designed, assembled, and tested at the Florida Solar Energy Center’s PV Materials Lab. This paper describes the synthesis and characterization of CIGSS thin-film solar cells by the RTP technique. Materials characterization of these films was done by scanning electron microscopy, x-ray energy dispersive spectroscopy, x-ray diffraction, Auger electron spectroscopy, electron probe microanalysis, and electrical characterization was done by current–voltage measurements on soda lime glass substrates by the RTP technique. Encouraging results were obtained during the first few experimental sets, demonstrating that reasonable solar cell efficiencies (up to 9%) can be achieved with relatively shorter cycle times, lower thermal budgets, and without using toxic gases.


2010 ◽  
Vol 297-301 ◽  
pp. 1439-1444
Author(s):  
Nicola Bianco ◽  
Oronzio Manca ◽  
Daniele Ricci

In this paper a numerical analysis on two-dimensional transient of the combined optical-thermal fields caused by a moving Gaussian laser source in a multilayer thin film structure on a glass substrate is carried out. The workpiece is considered semi-infinite along the motion direction and its optical and thermophysical properties are assumed temperature dependent. The COMSOL Multiphysics 3.4 code has been used to solve the combined thermal and electromagnetic problem. In this way, the optical field is considered locally one-dimensional and Maxwell equations are solved in order to evaluate the absorption in thin film. Results, in terms of transient temperature profiles and fields, are presented for different Peclet numbers and thin film thicknesses.


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

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