Growth and fundamental properties of SiGe bulk crystals

Yonenaga, Ichiro

doi:10.1016/j.jcrysgro.2004.10.071

Cited by 77 publications

(46 citation statements)

References 35 publications

(61 reference statements)

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“…In principle it is possible to grow germanium doped silicon (or Si 1−x Ge x ) crystals using the standard Czochralski pulling process with x up to 0.15 [3,4] although for x values above 0.05 special attention is needed to avoid dislocation formation and large diameter (> 4 inch) crystal growth has not yet been demonstrated.…”

Section: Czochralski Growth Of Germanium Doped Silicon Crystals and Dmentioning

confidence: 99%

“…Dislocation free Czochralski pulling of Si 1−x Ge x crystals is however limited to x values below a few percent although up to 15% has been demonstrated [3,4]. Germanium doping has been reported to enhance interstitial oxygen precipitation and out-diffusion [5,6], to suppress thermal donor (TDD) formation [7] and also to influence the COP density and size [8,9,10].…”

Section: Introductionmentioning

confidence: 99%

“…Doping with germanium has a beneficial effect on the yield strength of silicon and will thus reduce dislocation nucleation [4]. The effect on dislocation mobility and thus also on dislocation multiplication is however limited especially at high stress levels and much smaller than e.g.…”

Section: Introductionmentioning

confidence: 99%

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Germanium doping for improved silicon substrates and devices

Vanhellemont

Chen

Lauwaert

et al. 2011

Journal of Crystal Growth

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During the last decade, the 300 mm silicon wafer has been optimized and one is studying the move to 450 mm crystals and wafers. The ever increasing silicon crystal diameter leads to two important trends with respect to substrate characteristics: the interstitial oxygen concentration decreases while the size of grown in voids (COP's) in vacancy-rich crystals is increasing.The first effect is due to the large melt in which movements have to be controlled and partly suppressed by the use of magnetic fields. This magnetic confinement leads to a more uniform dopant incorporation but at the same time to a more limited transport of oxygen from the quartz crucible to the melt and the growing crystal. The reduced interstitial oxygen concentration and the lower thermal budget of modern device processing leads to strongly reduced oxygen precipitation and thus internal gettering capacity.The increasing COP size (accompanied by a decreasing density) is caused by the decreasing pulling rate and thermal gradient that have to be used in order to avoid dislocation formation. The slower cooling of the crystal leads to a decreased void nucleation rate and at the same time to an increased thermal budget for void growth as well as a larger number of vacancies available per void. Journal of Crystal Growth November 9, 2010 In the present paper the effect of germanium doping in the range between 10 16 cm −3 and 10 19 cm −3 on COP formation and oxygen precipitation is discussed and illustrated. Also the beneficial effect of germanium doping with respect to wafer breakage during processing, with respect to the suppression of thermal donor formation and with respect to improving device radiation hardness is addressed. Preprint submitted to

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Section: Czochralski Growth Of Germanium Doped Silicon Crystals and Dmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Germanium doping for improved silicon substrates and devices

Vanhellemont

Chen

Lauwaert

et al. 2011

Journal of Crystal Growth

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“…[10][11][12][13][14] Some of the main advantages of Ge doping on Si crystal quality are an enhancement of oxygen precipitation-important for large diameter wafers which have typically a low oxygen content-a reduced crystal originated particle ͑COP͒ size and flow pattern defect ͑FPD͒ density, see e.g., Ref. 10, and references therein.…”

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confidence: 99%

Impact of germanium on vacancy clustering in germanium-doped silicon

Chroneos

Grimes

Bracht

2009

Journal of Applied Physics

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The formation energy and thermal equilibrium concentration of vacancies in Ge doped Czochralski-grown Si are studied by quenching of samples annealed at temperatures between 1200 and 1350°C for 1 h under hydrogen atmosphere. After quenching, the majority of the formed vacancy and hydrogen containing point defect clusters are transformed into VH 4 defects by a 1 h anneal at 450°C. Measuring the amplitude of the vibrational band of VH 4 at 2223 cm −1 as function of the quenching temperature allows estimating the vacancy formation energy. An apparent formation energy of about 2 eV is obtained for Ge doping between 7 ϫ 10 17 and 6.5ϫ 10 20 cm −3 which is significantly lower than the 4 eV obtained for high purity Si. In the whole quenching temperature window, the vacancy thermal equilibrium concentration is significantly higher than in Si without Ge doping. It is shown that this lower apparent formation energy can be explained by the presence of vacancy traps. © 2010 American Institute of Physics. ͓doi:10.1063/1.3449080͔Intrinsic point defects in semiconductors play an important role in a wide range of processes ranging from Czochralski ͑Cz͒ crystal growth to device processing. In order to control and to optimize these processes, it is crucial to have a quantitative knowledge of the intrinsic point defect properties.In the early days already quenching from high temperatures has been explored to study the intrinsic point defects in Si. It was indeed observed that by quenching from high temperatures, donors are formed which change the resistivity of the Si material and can easily be detected using resistivity and Hall measurements. Unfortunately, it soon turned out that in most cases these donors were due to iron contamination either grown-in during crystal growth and activated by the quenching treatment or diffusing in from the surface of the samples during the high temperature treatment. 1 Often the concentration of iron was so high that it was the main cause of the observed resistivity changes. Only in few careful studies also donors were observed that could not be related to metallic impurities 2,3 but even in these cases the relation with the intrinsic point defects was not clear.For those reasons, beginning of the 1990s a new quenching technique was developed at Tohoku University which is based on performing the high temperature anneal and the quenching step itself with the sample kept under hydrogen ambient. [4][5][6][7] The originality of this approach is to detect vacancies as vacancy-hydrogen complexes. Isolated vacancies can indeed not exists after quenching because of the very small vacancy migration energy. Further more, ab initio calculations reveal that the binding energy of the various vacancy-hydrogen complexes that can be formed is larger than that of vacancy-only clusters with a similar number of vacancies. 8 Due to this, vacancies will preferentially cluster with hydrogen atoms/molecules during the quench and during subsequent low temperature anneals. After the quench from high temperature, an annea...

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“…Producing bulk material is most eciently done using the Czochralski technique. However, producing compositionally uniform material requires that silicon be replenished in the melt [2].…”

Section: Introductionmentioning

confidence: 99%

Seed Production and Melt Replenishment for the Czochralski Growth of Silicon Germanium

Armour

Dost

2013

Acta Phys. Pol. A

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The silicon transport in a silicongermanium melt has been studied to address the issues of melt replenishment and seed production for the Czochralski growth of silicon germanium (SiGe) crystals. The growth of SiGe single crystals by the Czochralski method requires that the melt be replenished with silicon during the growth process due to the rejection of germanium into the melt during solidication. To facilitate the replenishment of the melt, an accurate knowledge of the dissolution rate of silicon into the melt and its transport through the melt is required. To address these issues, a number of experiments have been carried out on the dissolution of silicon into a germanium melt. Liquid phase diusion growth experiments were also conducted for insight into transport and as a possible method for seed crystal production. The experiments encompassed various temperatures, crucible geometries, crucible translation, and magnetic eld levels to determine optimum conditions for the most favorable dissolution rates and mass transport in the melt. Results have shown that replenishment from bottom of the crucible is most eective due to the enhanced silicon transport by buoyancy. The application of magnetic elds may also provide an eective mean to control the replenishment rate (mass transport rate) in the melt.

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Growth and fundamental properties of SiGe bulk crystals

Cited by 77 publications

References 35 publications

Germanium doping for improved silicon substrates and devices

Germanium doping for improved silicon substrates and devices

Impact of germanium on vacancy clustering in germanium-doped silicon

Seed Production and Melt Replenishment for the Czochralski Growth of Silicon Germanium

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