Abstract: The role of single wafer Rapid Thermal Processing (RTP) in semiconductor
manufacturing has been steadily expanding over the last 2 decades. There are several reasons for the
successful adaptation of this technology. These include more critical requirements by advanced
semiconductor technologies with respect to thermal exposure and control, as well as tremendous
improvements by the RTP equipment community in resolving some fundamental limitations of the
tooling, historically restricting wide spread implementation. From rather humble beginnings, RTP
technology has now established itself as indispensable to the production of advanced semiconductor
products. We review the history and implementation of RTP technology in semiconductor
processing technology at International Business Machines Corporation (IBM) from the late 1980s to
Abstract: Rapid Thermal Processing (RTP) has been a key technology for semiconductor
manufacturing. The ability to rapidly change wafer-processing temperature in a well-controlled way
is a distinguishing characteristic of RTP. Today’s state of the art single wafer RTP equipment is
used for a wide range of thermal processes for the manufacturing of advanced semiconductor
devices. Two different designs of halogen lamp based RTP equipment dominate the applications.
The two equipment designs can be traced back to the early development of the semiconductor
industry before there was wide acceptance of RTP. Two junctures in the evolutions of these designs
resulted in the growth of RTP. The first juncture occurred when the conventional batch diffusion
furnace could not satisfy some of the thermal budget and ambient control process requirements for
semiconductor devices. A second juncture occurred with breakthrough developments in RTP
equipment that enabled better control and repeatability of the process temperature. Developments of
alternatives to tungsten halogen lamp based RTP will likely be seen in the future.
Abstract: The study of fast diffusion processes in materials requires short isothermal annealing
treatments combined with an accurate temperature measurement. The paper discusses the special
demands on rapid thermal annealing (RTA) devices in diffusion research and how these can be met
in practice. The scientific impact of RTA for diffusion research in semiconductors is demonstrated
by several examples dealing with fast impurities in Ge and Si.
Abstract: The use of Rapid Thermal Processing to install lattice vacancy profiles into silicon wafers
for the purpose of forming a template for the nucleation and ideal control of oxygen precipitation
has become an important materials engineering tool for the microelectronics industry. This paper
reviews the principles of the technique and the precise materials/defect engineering that it
engenders. It furthermore discusses what has been learned regarding the elusive properties of the
intrinsic point defects in silicon through studies of the distributions of vacancies created by use of
the technique. Also discussed are recent discoveries about the critical role of the other intrinsic
point defect, the self-interstitial and the development of oxygen precipitates and their distributions
post-nucleation and the critical importance of what has become to be called the “ninja
transformation” in the switching-on of gettering efficiency of oxygen precipitate systems.
Abstract: Significant performance enhancements are offered by silicon on insulator (SOI) or
strained silicon, SOI being adopted for advanced devices in sustaining Moore’s law. Sub-45 nm
device options are including fully depleted (FD) devices, that are stressing even more specifications
for thickness uniformity. Nano-uniformity, considering thickness variation contributions from
device level to wafer scale, has been introduced in substrate optimization and latest Unibond
products are verifying FD requirements. Rapid Thermal Processing (RTP) based surface smoothing
has been introduced in Unibond processing to combine thickness control and product quality
Abstract: An overview of various cleaning procedures for silicon surfaces is presented. Because in-situ
cleaning becomes more and more important for nanotechnology the paper concentrates on physical
and dry chemical techniques.
As standard ex-situ wet chemical cleaning has a significant impact on surface quality und thus
device properties, its influence on further processes is also considered. Oxygen and carbon are
unavoidable contaminations after wet chemical treatment and therefore we discuss their in-situ
removal as one of the main goals of modern silicon substrate cleaning. As surface roughness
strongly influences the electrical quality of interfaces for epitaxy and dielectric growth, we
concentrate on techniques, which meet this requirement.
It will be shown that multi-step thermal sequences in combination with simultaneous passivation
of the clean surface are necessary in order to avoid recontamination. This can be achieved not only
for ultra hich vacuum but also for inert gas atmosphere. In this case the process gases have to be
extremely purified and the residual partial pressure of contaminats such as oxygen and carbon has
to be negligible.
It will be demonstrated that 800°C is an upper limit for thermal treatment of silicon surfaces in
the presence of carbon because at this temperature SiC formation in combination with a high
mobility of silicon monomers leads to surface roughness. In addition mechanical stress causes
dislocations and crystal defects.