bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Oxygen for Ultra-Thin La2O3 Film Deposition
Authors: Tachi Kiichi , Iwai H. , Hattori Takeo , Sugii Nobuyuki , Tsutsui Kazuo , Ahemt Parhat , Kakushima Kuniyuki
Published: November 2006

We fabricated MOS capacitors consisting of a La2O3 dielectric with small EOT of 0.59 nm and a W electrode. By supplying oxygen during La2O3 deposition, La-silicate was formed at La2O3/Si interface. The La2O3 and La-silicate dielectric constant was 23.4 and 14.4, respectively. The depth of the trap potential well was small, compared to without oxygen. These differences resulted from the quantity of oxygen vacancy. Concerning the variation of annealing, stable capacitance and flat-band voltage were obtained up to 300{degree sign}C annealing. However, SiOx based interfacial layer formation was observed above 500{degree sign}C annealing.
The Improvement in Dielectric Characteristics and Reliability of Atomic-Layer-Deposited HfO2 Thin Films by In-Situ NH3 Injection
Authors: Kim Jeonghwan , Park Tae Joo , Cho Moonju , Seo Minha , Jang Jaehyuck , Hwang Cheol Seong
Published: November 2006

The improvements in reliability of atomic layer deposited (ALD) HfO2 thin films by an in-situ NH3 injection were studied. The HfO2 film with the in-situ NH3 injection was physically thinner than the HfO2 film without the NH3 injection although the number of ALD cycles was same. The degradation in dielectric performance by post-deposition annealing at 1000oC was more serious for the in-situ NH3 injected HfO2 film compared to the film without the NH3 injection. However, the leakage current degradation by the constant voltage stress (CVS) was much less for the in-situ NH3 injected HfO2 thin film. XPS analysis showed that the HfO2 film with the in-situ NH3 injection has a higher nitrogen concentration in the film which passivates the bulk traps in HfO2 layer and improves the leakage current degradation by the CVS.
Evaluation of Trisilylamine for HfSiOx Atomic Layer Deposition
Authors: Dussarrat Christian , Suzuki Ikuo , Yanagita Kazutaka
Published: November 2006

Hafnium silicon oxide thin films were grown by atomic layer deposition using a typical hafnium precursor (TDEAH, Hf(NEt2) 4), and a newly considered silicon precursor, trisilylamine (TSA, (SiH3)3N) with an ozone/oxygen mixture. The TSA molecule is a highly volatile molecule (315 Torr at 25 C) and is therefore easy to deliver into the reactor. TSA has the additional advantage of being carbon-free, hence minimizing the carbon incorporation. Deposits that were obtained exhibited smooth, featureless surfaces when deposited between 200 and 275 C at 1 Torr in a hot wall reactor.
Some Observations of Growth of CZ Silicon and Dream of Ideal Growth
Authors: Anttila Olli
Published: November 2006

Electronics industry as we know it today is largely based on Czochralski grown silicon. The basic crystal growth concept is essentially the same as almost 50 years ago, though major improvements have been established. Detailed understanding about what is really going on during the growth, and where the physical limits of the process might be, is still lacking.
Elimination of Dislocations in the Neck Growth
Authors: Sreedharamurthy Hariprasad , Nithianathan Vijay
Published: November 2006

A new method to grow necks that involves controlling the melt gap is developed. In this method, necks were grown by varying melt gap, which is the distance between melt surface and the reflector. Results show that, dislocations were completely eliminated at a length of 175 mm when the melt gap was 50mm, while the neck grown with a melt gap of 30 mm has dislocations present even at a neck length of 425 mm. Several 200mm crystals were grown with varying melt gap as part of experiments and it was confirmed by the evidences of loss of structure in the early body lengths, that necks grown with larger melt gaps were better to achieve structure. By changing melt gap, gradient at the solid liquid interface is changed. Controlling the gradient at the solid liquid interface, during neck growth is an effective method to grow robust necks.
Doping of Silicon Crystals with Bi and other Volatile Elements by the Pedestal Growth Technique
Authors: Riemann Helge , Abrosimov Nikolai , Noetzel Natalya
Published: November 2006

Monocrystalline, high purity FZ-Silicon doped with bismuth is a promising laser material for the not jet opened up THz- band. With pill-doping during the common FZ-process only a narrow axial part of the crystal could be doped at a sufficient level. Crystals with FZ-like purity and a longer, highly doped section were grown after the well known pedestal technique using a specially developed pill-doping method out from axial holes in the pedestal feed rod being caped by the molten zone. Also doping with lithium and magnesium was done In this way for the first time. The crystals had diameters of 15-20mm using slim 35mm feed rods. Therefore up-scaling of the growth process and, at least for Bi doping, a dislocation-free structure appear achievable.
Oxide Precipitatation via Coherent Seed -Oxide Phases
Authors: Kissinger Gudrun , Dabrowski Jarek
Published: November 2006

Until now, oxide precipitation is treated in theoretical models as homogeneous nucleation of incoherent SiOx precipitates. In reality, this type of nucleation is very seldom because it is hindered by a high energy barrier which results from the incoherent interface. The key role of VO2 complexes for nucleation of oxide precipitates was already demonstrated on a broad experimental basis. Ab initio calculations have shown that the agglomeration of VO2 is energetically favorable. In this contribution, the bulk modulus and molecular volume of nVO2 clusters, so-called seed-SiO2, are determined and an analytical nucleation model is developed. In a second step, a more advanced model was developed which is based on a mono- layered agglomeration of VO2 complexes on {100} planes, so called seed-SiO and the heterogeneous nucleation of amorphous SiO2 (a-SiO2) at these plates. From energetic reasons, the advanced model is regarded as the most plausible nucleation path.
Hydrogen-Related Donor Formation: Fabrication Techniques, Characterization, and Application to High-voltage Superjunction Transistors
Authors: Schulze Hans-Joachim , Buzzo Marco , Niedernostheide Franz-Josef , Rueb Michael , Schulze Holger , Job Reinhart
Published: November 2006

Hydrogen-induced doping can be used to create n-doped layers and columns in semiconductor devices. We investigated two techniques to form n-type layers and columns: Proton implantation followed by an annealing step in an inert atmosphere, and helium implantation followed by a hydrogen- plasma treatment. Spreading-resistance measurements and capacitance-voltage measurements were applied to analyze the doping distribution along the implantation direction. Scanning capacitance microscopy and light microscope images after selective etching were used for two-dimensional dopant profiling. Finally, we showed that hydrogen-related donor formation can be successfully applied to create high-voltage superjunction transistors.
Mechanical Stress and Defect Formation in Device Processing
Authors: Polignano Maria Luisa , Carnevale Gianpietro , Fantini Paolo , Mica Isabella
Published: November 2006

In this work we address the problem of estimating the mechanical stress and the related risk of crystal defect generation in a complex device process. The validity of numerical calculations of the mechanical stress developed in the device process flow is assessed by comparing the simulation results with the electrical measurements of test structures designed to monitor the dislocations formation and of other silicon strain sensitive structures. The results show that based upon numerical calculations it is possible to define mechanical stress criteria for preventing defect generation. By using this sort of criteria, potentially dangerous process variations can be easily identified. This method is quite general and can be applied to any device process flow. On the other hand, by comparing the electrical results of structures prone to defect generation and of stress-sensitive transistors with a non-critical geometry for defect generation, it is shown that after defect nucleation the elastic stress in non-critical structures and the defect- related failure fraction in critical structures may evolve into opposite directions. Therefore, suitable stress criteria are needed at all the levels in the process flow where crystal damage may cause defect nucleation. In this study it is also pointed out that a high temperature stress release annealing can be beneficial for stress reduction and defect prevention, but its position in the process flow is critical.
Modeling and Optimization of Internal Gettering of Iron in Silicon
Authors: Haarahiltunen Antti , Väinölä Hele , Yli-Koski Marko , Sinkkonen Juha , Anttila Olli
Published: November 2006

We present a model for heterogeneous precipitation of iron in silicon. In the model Fokker-Planck Equation is used to simulate the evolution of size distribution of iron precipitates. From the simulation results we may conclude, that in case of low levels of initial iron concentration (<1×1012 cm-3), internal gettering is difficult to achieve just by cooling. The low level of initial iron concentration can be gettered by using an additional nucleation step, which can be just a fast ramp to room temperature, before isothermal gettering anneal. We also analyze the effect of competitive gettering on the final iron concentration and the iron precipitate density profile. We found that internal gettering can reduce iron concentration and the particular advantage is the reduction of the iron precipitate density in the device layer. The iron precipitation in the device layer can also be reduced by increasing the doping concentration as the segregation increases.
Infrared Absorption Spectroscopy of Complexes in Low Carbon Concentration, Low Dose Irradiated CZ Silicon Crystal
Authors: Inoue Naohisa , Yamazaki Shinya , Goto Yasunori , Kushida Tomoyoshi , Sugiyama Takahide
Published: November 2006

Radiation induced complexes in low carbon concentration, low electron dose Czochralski silicon crystal are examined by infrared absorption spectroscopy. By using the highly sensitive, highly accurate measurement and arithmetic procedures, carbon-oxygen(-self interstitial) and vacancy- oxygen complexes are detected in samples with carbon concentration about 1x1016 atoms/cm3 and electron dose about 1x1015-16 atoms/cm2. Also, their concentrations are determined with estimated accuracy within a factor of two. It is shown that the complex concentration is proportional to the dose. Secondary defect formation is suppressed in such low carbon concentration and low dose samples. Quantitative analysis in high quality samples will provide important information on defect behavior in irradiated crystals.
Delineation of Crystalline Defects by Preferential Etching: Still more Alchemy than Science?
Authors: Kolbesen Bernd O. O.
Published: November 2006

Scaling-down of silicon based devices according to the International Technology Roadmap of Semiconductors requires besides many innovations regarding device concepts also the introduction of novel substrate materials such as silicon-on-insulator (SOI), SiGe or strained silicon-on-insulator (sSOI), providing, e.g. lower power consumption at higher device speed and enhanced carrier mobility compared to standard CZ silicon substrates without or with epitaxial layer. One of the challenges for the successful implementation of these materials into the mass production of advanced devices providing high yields and appropriate reliability is the characterization and monitoring of their crystal quality and defect densities. It is well known that the thin Si layers (some ten to hundred nanometer thick) of SOI substrates may contain imperfections and crystalline defects such as vacancy agglomerates (D defects). SiGe films and strained Si layers of sSOI substrates exhibit misfit and threading dislocations as well as stacking faults and twins.
Evaluation of Silicon Photovoltaic Devices with Near-Field Scanning Optical Microscopy
Authors: Wagener Magnus C. , Rozgonyi George
Published: November 2006

This report presents the use of near field scanning optical microscopy (NSOM) as a complementary tool for photovoltaic investigations requiring a significantly higher degree of spatial resolution and sensitivity. The applicability of near-field photocurrent contrast imaging to cast silicon material and nano-crystalline silicon thin-film is demonstrated. The recombination efficiency of individual dislocation arrays was resolved and revealed secondary bands of reduced collection efficiency adjacent to each dislocation array. The collection uniformity of a nano-crystalline silicon thin film was also successfully imaged.
DLTS Study of Room-Temperature Defect Annealing in High-Purity n-Type Si
Authors: Bleka Jan , Monakhov Eduard V. , Avset Berit S. , Svensson Bengt G.
Published: November 2006

Deep-level transient spectroscopy (DLTS) measurements have been performed on p(+)-n(-)-n(+) Si-diode detectors produced from low-doped ([P] = 5 × 1012 cm-3), high-purity MCz-Si and Fz-Si wafers. After irradiation with 6-MeV electrons to a dose of 5 × 1012 cm-2, the vacancy-oxygen (VO), doubly negatively charged divacancy (V2(=/-)) and singly negatively charged divacancy (V2(-/0)) complexes are observed. There is also the clear presence of a defect with an energy level slightly shallower than that of V2(-/0) and the concentration ~ 1/4 that of V2. The samples were kept at room temperature (RT), and the defect concentration was seen to reduce to half during five weeks. A closer examination revealed a similar peak overlapping that of V2(-/0).
Regular Dislocation Networks in Silicon as a Tool for Novel Device Application
Authors: Kittler Martin , Reiche Manfred , Seifert Winfried , Yu X. , Arguirov T. , Vyvenko Oleg , Mchedlidze Teimuraz , Wilhelm Thomas
Published: November 2006

The paper deals with possibilities of utilizing dislocation structures as active components of devices. The suggested means for controlled formation of dislocations is direct wafer bonding, giving rise to well defined dislocation networks with adjustable properties. It is shown that the networks allow building light emitting diodes based on the D line luminescence of the dislocations. A light emitter at about 1.5 mm wavelength is demonstrated, with an efficiency potential estimated at 1%. Immobilization of biomolecules on Si surfaces by Coulomb interaction with the dislocations in the network is another application discussed. Finally, the potential use of dislocation networks as insulating layers permeable to impurities to be gettered and as three-dimensional buried conductive channels in the Si wafer is addressed.
New Silicon-Based Materials for Spintronics Applications - Si:V and Si:Cr
Authors: Misiuk Andrzej , Chow Lee , Barcz Adam , Surma Barbara , Bak-Misiuk Jadwiga , Romanowski P.
Published: November 2006

We present here two new silicon-based materials for possible applications as spintronics materials. These materials are based on high dose ion implantation of transition metal ions, V+ or Cr+ into a single crystalline silicon wafer. After ion implantation, thermal anneals at high temperatures and high hydrostatic pressures are carried out in a high pressure chamber. Secondary ion mass spectrometry is used to characterize the re-distribution of the implanted atoms after thermal anneals; photoluminescence and X-ray techniques are applied to check microstructure of the samples. A variable temperature SQUID magnetometer is used to measure the magnetic properties of the processed samples. It is found that some of the samples showed ferromagnetic hysteresis loops at low temperatures. Implications of our findings are discussed in terms of future applications of spintronics materials based on ion-implanted silicon.
CMOS Photonics Using Germanium Photodetectors
Authors: Gunn Cary , Masini Gianlorenzo , Witzens J. , Capellini G.
Published: November 2006

Today, CMOS Photonics technology has matured so that most waveguide based optical functions are available inside a CMOS die. While an integrated light source is still an outstanding problem, photodetection can be accomplished by the addition of pure germanium photodetectors to the CMOS process. These components have the potential to enable outstanding sensitivity levels when integrated monolithically with CMOS circuitry.
Electron Transport in Engineered Substrates: Strain, Orientation, and Channel/Insulator Material Effects
Authors: Fischetti Massimo , Narayanan Sudarshan , O'Regan Terrance , Sachs Cathy
Published: November 2006

We present theoretical results regarding electronic transport in different types of `unconventional' substrates and structures: (a) In uniaxially and biaxially strained Si for a variety of substrate, transport-direction and strain orientations, showing that compressive strain on (110) surfaces may enhance simultaneously the electron and hole mobility; (b) In short-channel Si, Ge, and InGaAs bulk and double-gate FETs, showing that at the 15 nm length the `density-of-states' bottleneck reduces drastically the performance of small-mass materials. We also discuss the role of Zener leakage in these small devices, process which is particularly severe in Ge devices; (c) In Si and Ge high-k systems, showing that electron mobility in Ge inversion layers is also seriously affected by high-k phonons, but that the loss of performance -- measured in terms of transconductance -- vanishes at short channel length for both Si and Ge devices.
Fast Ge-on-Si Photodetectors for the Near Infrared
Authors: Colace Lorenzo , Masini Gianlorenzo , Assanto Gaetano , Luan Hsin-Chiao , Kimerling Lionel, K
Published: November 2006

We report on the state of the art of near infrared photodetectors based on germanium on silicon. After a brief review on material and devices, we describe our approach to the fabrication of fast Ge/Si p-i-n detectors based on a simple process with reduced thermal budget for compatibility with standard silicon technology. The diodes, fabricated by chemical vapor deposition at 600ºC, exhibit responsivities of 0.4 and 0.2A/W at 1.3μm and 1.55μm, respectively, and operation at 10Gbit/s.
Design of Spontaneous Emission Enhancement Based on Si Ring Resonators
Authors: Miki Yasumasa , Yamada Koji , Watanabe Toshifumi , Tsuchizawa Tai , Fukuda Hiroshi , Itabashi Seiichi , Ozaki Hiroaki , Hirano Shingo , Wada Kazumi
Published: November 2006

In this research we designed and fabricated Si ring resonators to realize Si light emitter by the enhancement of spontaneous emission in terms of the Purcell effect. In the result we got high unloaded Q factor about 110000 and high Purcell factor about 100. This result suggests the overcoming of the thermal quenching of rare earthes in Si
Investigation of Fabrication Process for n+/p Junction for Germanium n-channel MOSFETs
Authors: Koike Masahiro , Kamata Yoshiki , Ino Tsunehiro , Hagishima Daisuke , Koyama Masato , Nishiyama Akira
Published: November 2006

The profiles of the impurity concentrations and carrier concentrations of n-type dopants (As and P) in Ge(100) substrates have been investigated to fabricate n+/p junctions for Ge n-channel MOSFETs with a low resistivity n+Ge layer. It has been found that P had higher activation levels than As. We discuss a possible mechanism for the difference in activation behaviors between P and As.
Carbon Incorporation in SiGe Epi Films to Block Boron Diffusion
Authors: Deleglise Florence , Dutartre Didier , Talbot Alexandre
Published: November 2006

This paper quantifies using Room Temperature Photoluminescence (PL) the substitutional carbon incorporation in SiGe epitaxial films at a function of the deposition temperature. Thanks to SIMS analysis, the better substitutional carbon incorporation at low deposition temperatures is shown to reduce the boron diffusion from SiGeC films.
Tensile Strained Selective Silicon Carbon Alloys for Recessed Source Drain Areas of Devices
Authors: Bauer Matthias , Weeks Doran , Zhang Yangting , Machkaoutsan Vladimir
Published: November 2006

Si1-yCy films grown lattice matched into recessed source drain areas can produce a tensile strained Silicon channel, which in turn will enhance electron mobility. We demonstrate a Cyclical Deposition Etch (CDE) process that consists of a nonselective deposition, (epitaxial growth over the exposed crystalline Silicon areas of the source and drain and amorphous (a) or polycrystalline deposition over the dielectric areas) together with a subsequent selective removal of a-material from the insulator, with negligible removal of epitaxial material from source and drain areas. To make such an approach production worthy, two requirements are essential: 1) a high growth rate (GR) with a low a/epi GR ratio, and 2) a high etch rate (ER) with a high a/epi ER ratio. We focus on the integration and defect formation aspect of our CDE process on patterned substrates.
Investigation of Silicon-Germanium Films Deposited by Plasma-Enhanced Chemical Vapor Deposition Using Laser Assistance
Authors: Lee Ching-Ting , Cheng Jun-Hung , Chen Yao-Ming , Tsai Tai-Cheng
Published: November 2006

To avoid the undesirable thermal treatment in high temperature, we proposed a new technique to deposit Si-Ge films on Si substrate in room temperature and without thermal post- annealing process. Since CO2 laser can be used as an energy source to induce gas-phase pyrolysis of SiH4 in a reactor, we used CO2 laser to assist the deposition of Si-Ge films on Si substrate in a conventional plasma-enhanced chemical deposition system (PECVD). An external CO2 laser beam with a wavelength of 10.6 μm was guided into the chamber of the conventional PECVD system. To deposit Si-Ge films on Si substrate without heating, argon-diluted SiH4 (4%) and GeH4 were used as reactant gas sources. In this study, the surface morphology of a-SiGe:H thin films grown with various laser power densities was examined using atomic force microscopy (AFM). The bonding configuration was analyzed by Raman spectroscopy and Fourier transmission infrared (FTIR) spectroscopy.
Effectiveness of Si Seed for Selective SiGe Epitaxial Deposition in Recessed Source and Drain for Locally Strained pMOS Application
Authors: Cheng Po Lun , Liao Chin I , Wu Hou Ren , Chen Yi Cheng , Chien Chin Cheng , Yang Chan Lon , Tzou S F , Tang Jinsong , Cho Yonah , Sanchez Errol , Chang Vincent C , Fu Tony , Hsu Wen S.
Published: November 2006

A thin layer of Si seed was employed to help nucleate low- temperature selective SiGe epitaxial film in recessed source and drain areas. In combination with pre-epi wet clean and low- temperature chemical bake, use of Si seed resulted in improved SiGe film morphology and micro-loading effect, and further improved dislocation on the lateral recessed interface.
Power Gain Characteristics of RF MOSFETs under Different Configurations
Authors: Jiang Ningyue , Yuan Hao-Chih , Ma Zhenqiang
Published: November 2006

The power gain characteristics of MOSFET under common-source (CS) and common-gate (CG) configurations are analytically studied and verified with simulations using RF MOSFET large- signal models. The substrate parasitic effects on the power gain characteristics are also investigated. While little impact is observed on the CS power gain characteristics due to substrate parasitics, the power gain characteristics of the CG configuration are greatly and adversely influenced. High- frequency power-gain characteristics can be improved for the CG configuration with reduced substrate effects and lowered gate resistance values. The power gain potential of CG configuration could be eventually realized by using high- resistivity or SOI substrate and gate stacks of lower resistance.
Study of Charged States of Si Quantum Dots with Ge Core
Authors: Makihara Katsunori , Ikeda Mitsuhisa , Higashi Seiichiro , Miyazaki Seiichi
Published: November 2006

Si quantum dots with Ge core were self-assembled on thermally- grown SiO2 from thermal decomposition of alternately pure SiH4 and GeH4 diluted with He. Changes in the surface potential caused by electron charging to and discharging from individual Si dot with and without Ge core were studied by using a Kelvin probe technique in atomic force microscopy (AFM). The potential change attributable to the extraction of one electron from a Si dot with Ge core was observed after tapping an AFM tip biased at +1.2V while for pure Si dot with almost the same size, the tip bias required for causing a similar potential change was as high as +3.0V. Also there was no significant difference in tip bias for electron injection between Si dot with and without Ge core. The result suggests an energy band structure in which Ge core act as a deep potential well for holes but less modulate the conduction band. Correspondingly, stable positively-charged states for Si dots with Ge core were confirmed in comparison with pure Si dots.
Control of Carbon Incorporation in Selectively Grown Epitaxial SiGe:C Layers Dedicated to HBTs
Authors: Vandelle Benoit , Brossard Florence , Barbalat Benoit , Chevalier Pascal , Saguin Fabienne , Dutartre Didier
Published: November 2006

The fabrication of high speed npn SiGe HBTs requires the use of carbon to inhibit boron diffusion. The incorporation of carbon in SiGe films must be accurately controlled to avoid the formation of C-related defects. This paper describes a method which allows the development of SiGe:C processes for high performance HBTs based on photoluminescence analysis.
Silicon-Germanium Heterostructure-on-Insulator Formed by Ge+ Ion Implantation and Hydrogen Transfer
Authors: Popov Vladimir P. , Tyschenko Ida E. , Cherkov Alexander G. , Voelskow Matthias -.
Published: November 2006

Using bulk silicon can be ended for 32 nm technological nodes. New type of substrates needs for further scaling in CMOS microelectronics. We speculate that these new type of materials will be semiconductor heterostructure on insulator (SHI) compatible with current silicon planar CMOS technology. Joint semiconductor material stack placed on cheap amorphous dioxide is presented. First of all thin film SiGe heterostructure properties is considered. It was obtain using Ge ion implantation in dioxide with followed Ge segregation to the directly bonded interface between silicon and silicon dioxide wafers. The method is also compatible with A3B5 thin film formation.
Strained Silicon Two-dimensional Electron Gases On Commercially Available Si1-xGex Relaxed Graded Buffers
Authors: Yao Kun , Sturm James , Lochtefeld Anthony
Published: November 2006

In this work, we describe the growth of two-dimensional electron gas (2DEG) structures in strained Si on commercially available SiGe relaxed graded buffers with 20% Ge fraction. Most work to date on 2DEG's focuses on x=0.3 and above for larger conduction band offsets. In this work we demonstrate the suitability of commercially available relaxed buffers for these structures, for eventual quantum computing applications based on the spin of electrons in Si. The use of commercially available buffers is desirable because of their very high quality and because it is often difficult for a single system to grow both the thick buffer and the thin precise layers for 2DEG's. 20% Ge buffers are used because higher Ge fractions are not easily commercially available. The modulation of the electron gases we grow using atomic layer deposited (ALD) Al2O3 is also demonstrated.
Local Strain Characterization on Strained-Si/SiGe Heterostructures with Convergent Beam Electron Diffraction and Finite Element Simulation
Authors: Zhao Wenjun , Duscher Gerd , Zikry Mohammed , Rongonyi George
Published: November 2006

We introduce a novel and reliable method to quantify local strain variation in microelectronic device structures based on convergent beam electron diffraction (CBED) and finite element (FE) calculation. The match of the finite element calculation results with the experimental data not only validated the parameters used for the finite element simulations, but also gives us insights into the origin of high order Laue zone (HOLZ) line splitting in a lattice-mismatched heterostructure. The 2D and 3D calculations showed that the residual strain measured from clean and sharp CBED patterns deviate from the initial strain. The effect of a SiO2 layer on the strain in a TEM sample was also investigated by FE simulation and we found that a SiO2 layer can suppress some of the elastic deformation making it possible to obtain clean and sharp CBED patterns. The here proposed novel method uses the elastic deformation to determine the initial strain in microelectronic devices structures by combining FE simulations and CBED patterns.
Pushing the Performance Limits of SiGe HBT Technology
Authors: Khater Marwan H. , Adam Thomas , Rieh Jae-Sung , Schonenberg Kathryn , Pagette Francois , Stein Kenneth , Jeng Shwu-Jen , Ahlgren David , Freeman Gregory
Published: November 2006

The implementation of challenging novel materials and process techniques has led to remarkable device improvements in state- of-the-art high-performance SiGe HBTs, rivaling their III-V compound semiconductor counterparts. Vertical scaling, lateral scaling, and device structure innovation required to improve SiGe HBTs performance have benefited from advanced materials and process techniques being developed for next generation CMOS technology. In this work, we present a review of recent process and materials development enabling operational speeds of SiGe HBTs in excess of 350 GHz. In addition, challenges of new process technologies and materials implementation to improve the device performance will be discussed.
Strain Control of Stripe Patterned Si/Si1-xGex/Si(100) Heterostructures
Authors: Uhm Jangwoong , Sakuraba Masao , Murota J.
Published: November 2006

In Si/Si1-xGex/Si(100) heterostructure patterned into stripe shape with <110> direction, strain control of capping Si and Si1-xGex layers is investigated. The Raman scattering analysis of the stripe patterned Si/Si1-xGex/Si(100) heterostructure indicates strain relaxation in Si1-xGex layer and introduction of tensile strain into capping Si layer by submicron stripe patterning. It is found that the effect of heat-treatment (750ºC, 3 h) on the strain relaxation in Si0.6Ge0.4 layer of stripe has a negligibly small. The metal-oxide-semiconductor capacitor and photoluminescence measurements for strain controlled stripe patterned Si/Si1-xGex/Si(100) heterostructure shows the change of energy band structure.
Strain Modeling in Advanced MOSFET Devices
Authors: Cea Stephen , Ghani Tahir , Giles Martin , Kotlyar Roza , Matagne Philippe , Mistry Kaizad , Obradovic Borna , Shaheed Reaz , Shifren Lucian , Stettler Mark , Tyagi Sunit , Wang Xiaoling , Weber Cory , Keys Patrick
Published: November 2006

Due to the success of using strain for performance gain in advanced logic technologies, strain engineering has become an important part of advanced transistor design. This paper presents process and device models that are used to provide understanding of process-induced stress such as the stress due to epitaxial SiGe source drains and nitride capping films and how that stress affects device performance.
On the Influence of the Position-Dependence of Stress on Device Performance
Authors: Bufler Fabian M. , Gautschi Ralf
Published: November 2006

We investigate the effect of the position-dependence of stress on device simulation in a 65 nm node technology using mechanical simulations for the stress created by a nitride liner in the n-MOSFETs and by SiGe source/drain pockets in the p-MOSFETs. For gate lengths below 0.1 μm, the difference in the linear and especially the saturation drain current becomes negligible when either considering the position-dependence of stress or using a constant stress picked from the source-side of the channel. In contrast, significant differences in the current enhancements exist for different mobility models (linear piezoresistance versus Intel hole mobility model) and different transport equations (drift-diffusion versus hydrodynamic).
Analysis of Hole Transport in Arbitrarily Strained Germanium
Authors: Karlowatz Gerhard , Ungersboeck Enzo , Kosina Hans , Wessner Wilfried , Selberherr Siegfried
Published: November 2006

Full-band Monte Carlo simulations are performed to study the properties of hole transport in bulk Germanium under general strain conditions. The band structures are calculated with the empirical non-local pseudopotential method. For Monte Carlo simulations acoustic and optical phonon scattering as well as impact ionization are taken into account. Results for biaxially strained Ge grown on a [001] oriented SiGe substrate and for uniaxial compressive stress in [110] exhibit a high mobility enhancement.
Application of Selective Si:C Epitaxy For Recessed Source/Drain Technology
Authors: Kim Yihwan , Ye Zhiyuan , Zojaji Ali , Lam Andrew , Sanchez Errol , Kuppurao Satheesh
Published: November 2006

We have developed selective Si:C epitaxy process with 1 % substitutional carbon concentration to fill 60 nm deep recessed areas with 100 % selectivity. The process does not show loading effects of thickness and substitutional carbon concentration on patterned wafer. Different growth behavior on sidewall of the recessed area is observed compared to that on the recessed bottom, that causes a non-flat film surface profile.
In-Situ HCl Etching and Selective Epitaxial Growth of B-doped Ge for the Formation of Recessed and Raised Sources and Drains
Authors: Hartmann Jean-Michel , Papon A.-M. , Fabbri J. M. , Rolland Guy , Billon Thierry , Juhel Marc , Halimaoui Aomar
Published: November 2006

The aim being the integration of either recessed or raised Ge:B Sources and Drains(S/Ds), we have studied the growth kinetics and the insitu boron doping of Ge in Reduced Pressure- Chemical Vapour Deposition. The Ge growth rate at 400ºC, 60 Torr on blanket Si(001) is lower when adding HCl to GeH4. The B atoms concentration increases linearly with the F(B2H6)/F(GeH4) mass flow ratio (maximum: 3.5x1019cm3). 20% to 40% of (almost all) the B atoms are electrically active in Ge:B layers grown at 400ºC (subsequently annealed at 750ºC under H2 for 10 minutes). The macroscopic degree of strain relaxation R of as grown Ge layers increases slowly from 92% up to 100% as the Ge layer thickness increases. We have also studied the kinetics of the insitu HCl etching at 20 Torr of recess in the Si active regions of patterned wafers.
Novel Process Development for Bilayer Embedded SiGe Source/Drain Formation
Authors: Miyanami Yuki , Ota Kazunobu , Shinyama Takashi , Owa Yu , Katagiri Takahiro , Horiuchi Atsushi , Hagimoto Yoshiya , Watanabe Koji , Ikuta Tetsuya , Terauchi Sanae , Nagaoka Kojiro , Fujita Shigeru , Naruse Hiroshi , Mizushima Ichiro , Iwamoto Hayato , Nagashima Naoki , Kadomura Shingo
Published: November 2006

We have developed a new technique of bilayer embedded SiGe epitaxy in order to suppress the degradation of short channel characteristics in PFETs. We have found that the SiGe growth rate near the recess side wall increased when using a high SiH2Cl2 flow at high pressure. It enabled 1st conformal undoped SiGe layer growth for the recess shape. For the 2nd SiGe layer, we used an appropriate B2H6flow rate for good morphology. XAFS revealed that the 2nd nearest neighbors of Ge became distorted when the incorporated amount of B increased. In addition, we developed a Simultaneous condition switching technique for forming bilayer embedded SiGe.
Characterization and Modeling of Atomically Sharp Perfect Si:Ge/SiO2 Interfaces
Authors: Windl Wolfgang , Liang Tao , Lopatin Sergei , Duscher Gerd
Published: November 2006

Using ab-initio calculations and atomic-resolution Z-contrast imag-ing and electron energy-loss spectroscopy, we show that oxidation of a germanium-implanted Si surface can produce an atomically-sharp interface with a band structure that seems to be more favor-able for use in electronic devices than the usually diffuse interface in Si/SiO2. Furthermore, we propose an ab-initio based Monte-Carlo model to simulate oxidation of SiGe alloys to better under-stand the formation of the sharp interface.
Selective Epitaxial Growth Of Si And Relaxed Ge By UHV-CVD In Si(001) Windows
Authors: Fossard Frédéric , Halbwax Mathieu , Yam Vy , Nguyen Huu Lam , Mathet Véronique , Cammilleri Davide , Débarre Dominique , Boulmer Jacques , Bouchier Daniel
Published: November 2006

Relaxed germanium was deposited following a low temperature-high temperature procedure by ultrahigh vacuum chemical vapor deposition in Si trenches opened through a SiO2 mask. The resulting growth is selective, the germanium fills the Si trenches and evolves towards a roof-shaped morphology limited by (001), {113} and {111} facets. The evolution in height of the Ge structure depends on the trench width, and can be understood by considering a growth rate in the <113> direction equal to 22% of that measured along the <001> axis. At last, a surprisingly strong Ge diffusion under the SiO2 mask was revealed by selective chemical etching. Such a phenomenon was unexpected because no diffusion through the Si/Ge interface was previously observed on plain wafer.
In Situ Phosphorus Doping of Germanium by APCVD
Authors: Dilliway Gabriela , Van Den Boom Ruud , Moussa Alain , Leys Frederik , Van Daele Benny , Parmentier Brigitte , Clarysse Trudo , Simoen Eddy R. , Defranoux C. , Meuris Marc M. , Benedetti Alessandro , Richard Olivier , Bender Hugo
Published: November 2006

The in-situ fabrication of rectangular concentration-depth profiles of phosphorus in germanium, with electrically active concentrations approaching 1020 cm-3 is reported. The growth method is atmospheric chemical vapor deposition using germane and phosphine with N2 as carrier gas. Best results have been achieved using a relatively low growth temperature of 350ºC and a low PH3/GeH4 flow ratio, enabling a high concentration of P to be incorporated substitutionally. No P clusters are visible in high-angle annular dark-field STEM images. The results show excellent crystalline quality and acceptable surface uniformity, achieved with growth rates in the range of 5-10 nm / min. There is evidence that further improvements in active concentrations may be achievable by a further reduction in growth temperature and optimization of the gas flow conditions. The process holds promise for future n+junction fabrication in germanium.
Isotropic Etching of Si1-xGex Buried Layers Selectively to Si for the Realization of Advanced Devices
Authors: Borel Stéphan , Caubet Véronique , Bilde Jeremy , Cherif Anissa , Arvet Christian , Vizioz Christian , Hartmann Jean-Michel , Rabille Gilles , Billon Thierry
Published: November 2006

The selective removal of a SiGe sacrificial layer in a Chemical Dry Etching (CDE) mode is reported. The process parameters have been optimized in order to minimize the consumption of the surrounding Si in advanced 3D structures. The impact of parameters such as the Ge content, the SiGe layer's thickness or the nature of the mask has also been investigated in order to have a global understanding of the etching mechanisms. The optimal process conditions have been tested on devices of which electrical performances have completed the morphological characterization of the etching recipe.
A Study of Boron Implantation into High Ge Content SiGe Alloys
Authors: Wittmann Robert , Uppal Suresh , Hoessinger Andreas , Cervenka Johann , Selberherr Siegfried
Published: November 2006

We report an experimental and simulation study for introducing Boron ions into high Ge content SiGe alloys and into Ge.The larger nuclear and electronic stopping power of the Ge atom is responsible for the trend to shallower profiles with increasing Ge content in SiGe alloys. We found that the higher displacement energy in Ge, the stronger backscattering effect, and the smaller energy transfer from the ion to the primary recoil of a collision cascade are mainly responsible for the significantly reduced damage in pure Ge.
Stimulated THz Emission of Strained p-Ge and SiGe/Si Quantum-Well Structures Doped with Shallow Acceptors.
Authors: Kagan Miron S. , Altukhov Igor , Sinis Valeriy , Chirkova Elena , Paprotskiy Stanislav , Yassievich Irina , Odnoblyudov Maksim , Prokofiev Aleksey , Kolodzey James
Published: November 2006

The origin and properties of stimulated terahertz (THz) emission in uniaxially compressed p-Ge and strained SiGe/Si quantum-well structures doped with shallow acceptors are discussed. The THz emission is associated with the stimulated optical transitions between resonant and localized acceptor states. Spectra of the emission are presented. The regimes of emission excitation and possibility of cw operation are examined.
Silicon-Germanium Saturable Absorber Mirrors for Ultra-Short Pulse Generation
Authors: Kaertner Franz X. , Byun Hyunil , Grawert Felix , Gopinath Juliet , Shen Hanfei , Ippen Erich , Akiyama Shoji , Liu Jifeng , Wada Kazumi , Kimerling Lionel, K
Published: November 2006

Silicon-Germanium saturable absorber mirrors are developed for laser mode locking. The fabrication process is fashioned such that a highly reflecting Si/SiO2 Bragg mirror with a crystalline absorber top-layer is generated. One step of wafer- bonding allows for subsequent epitaxial growth on the mirror. A six-pair reflector centered at 1400 nm with 99.8% peak reflectivity, a 99%-reflectivity bandwidth of 700 nm and a surface roughness of 0.136 nm is demonstrated. A thin Germanium layer is epitaxially deposited on the mirror surface to provide saturable absorption at 1550nm. with a sub- picosecond recovery time. The device is used to achieve stable, continuously modelocked operation of an Er-Yb:glass laser centered at 1540 nm, generating 220 fs pulses.
Polycrystalline Germanium on Silicon for Near Infrared Detectors
Authors: Colace Lorenzo , Masini Gianlorenzo , Assanto Gaetano
Published: November 2006

The diffusion of optical communications is still hindered by the high cost of transceivers operating in the near infrared. Such systems are currently realized by hybrid integration of sources, modulators, detectors and control/processing electronics. The development of a Silicon-compatible technology for the fabrication of sources and detectors is expected to dramatically reduce transceivers costs through a more mature technology (compared to III-V semiconductors) and monolithic integration (possibly including amplifying and biasing electronics) on a single optoelectronics integrated circuit (OEIC). Germanium-on-Silicon detectors have been introduced for the wavelengths of interest (1.3 and 1.6 µm), with characteristics comparable with those of commercial III-V (InGaAs, InGaAsP) photodiodes.
Key Issues for the Development of a Ge CMOS Device in an Advanced IC Circuit
Authors: Meuris Marc M. , Martens K. , De Jaegar B. , Van Steenbergen J. , Bonzom Renaud , Caymax Matty R. , Houssa M. , Kaczer Ben , Leys Frederik , Nelis Daniel , Opsomer Karl , Pourghaderi A. M. , Satta A. , Simoen Eddy R. , Terzieva Valentina , Souriau Laurent , Bellenger F. , Brammertz Guy , Nicholas G. , Scarozza M. , Huyghebaert C. , Winderickx Gillis , Loo Roger , Clarysse Trudo , Conard Thierry , Bender Hugo , Benedetti Alessandro , Todi R. , Delabie A. , Hellin David , Van Daele Benny , Sioncke Sonja , Mertens Paul W. , De Meyer Krtistien , Van Elshocht Sven , Vandervorst Wilfried , Zimmerman Paul , Brunco David P. , Heyns Marc M.
Published: November 2006

Passivation of the channel in the gate stack is the most important problem for introducing another material than silicon into the channel of CMOS devices. In order to compare the mobility values of different passivation techniques, we propose to use a parameter, which is a proportional to the drive current of the transistor. We call this parameter the channel mobility value and it is calculated from the transistor equation. This channel mobility value can be used to benchmark more consistently the different passivation techniques on germanium or other semiconductor materials. A second issue for CMOS scaling on Ge is the poor performance of nMOS devices and there seems no solution in sight for this problem. Therefore we promote the investigation of technologies to allow the introduction of III-V materials on Ge to make nMOS devices in III-V devices complementary with Ge pMOS. A third key issue is the development of a manufacturable and low defect density germanium-on-insulator (GeOI) technology on 200mm and larger substrate sizes.
The Deposition of Polycrystalline SiGe with Different Ge Precursors
Authors: Shi Xiaoping , Schaekers Marc , Leys Frederik , Loo Roger , Caymax Matty R. , Brus Stephan , Zhao Chao , Lamare Bruno , Woelk Egbert , Shenai Deo
Published: November 2006

This paper reports on the development of poly-SiGe deposition in single wafer CVD systems. First silane and germane are used as precursors. The deposition temperature ranges from 500ºC to 610ºC. The film composition, texture, deposition rate, and surface morphology have been studied for a range of deposition conditions. Since the cracking temperature of GeH4 is much lower than that of SiH4, it is not straightforward to reach higher than 70% Ge. A new Ge precursor, Dimethyl (Amino) Germanium Trichloride (DMAGeCl), is developed to extend the Ge concentration range. The deposition of poly-SiGe with silane and the new Ge precursor, DMAGeCl, is studied. The results about the film composition, texture and deposition rate are reported. Poly-SiGe films with Ge content up to 80% are easily achieved.
Development of Novel Germanium Compounds for Use in SiGe Epitaxy
Authors: Shenai Deo , DiCarlo Ron , Power Mike , Amamchyan Art , Goyette Randy , Woelk Egbert , Sagnes Isabel
Published: November 2006

Today, one of the major limitations impacting the commercialization of SiGe technology is the lack of a commercially viable and safer process that eliminates hazards associated with GeH4 and higher thermal budget associated with GeCl4. The key to growing successful SiGe structures is thus a strategic deposition process that (a) employs safer germanium sources, and (b) offers a wide growth temperature window without degrading the film properties and jeopardizing the environment, health and safety (EHS) aspects of overall operation. In this paper, we report on the development of novel germanium precursors along with the first successful use of an enabling germanium precursor, isobutyl germane (IBGe) for the growth of high purity Ge and SiGe films. We also elucidate our strategy to identify the most appropriate candidates from a large number of promising organogermanium compounds along with initial results on SiGe films and high quality epitaxial Ge films deposited using IBGe.
Integration of Photonic Detectors in Standard SiGe HBT BiCMOS
Authors: Meinhardt Gerald , Kraft Jochen , Zimmermann Horst
Published: November 2006

The currently emerging optical data storage technologies of Blu-Ray Disk, respectively High Density Digital Versatile Disk (HDDVD), have opened a new field of activity for photodetectors preferentially integrated in a SiGe heterojunction transistor (HBT) BiCMOS process platform. Besides the advantages this process offers for analog signal processing we show how HBT process modules can be used to integrate fast, high-responsivity photodetectors sensitive to blue, red and near-infrared light of wavelengths 405, 660 and 785nm, respectively. The tradeoffs made for tuning HBT performance are discussed with respect to their impact on photodiode performance. The integration of the photodetector can be carried out with layout changes only not altering any other process step making it therefore an easy-to-do and free- of-extra-cost extension of the HBT BiCMOS base process.
Effects of Proton Radiation on Device Modeling of SiGe Power HBTs
Authors: Jiang Ningyue , Ma Zhenqiang , Ma Pingxi , Racanelli Marco
Published: November 2006

The effects of proton irradiation on device modeling of SiGe power HBTs are investigated in this work. On-wafer DC, small- signal AC, linearity and large-signal load-pull measurements were performed before and after proton irradiation. Minor degradation in DC, small-signal AC and large-signal load-pull characteristics and minor improvement in linearity are well modeled with the extraction of model parameter changes after radiation. It is found that the major changes that influence the device performance of SiGe power HBTs after proton radiation are the increase of base and emitter resistances.