Effect of extended phosphorus diffusion gettering on chromium impurity in HEM multicrystalline silicon

Khelifati, N.; Bouhafs, D.; Boumaour, M.; Abaidia, S.E.H.; Palahouane, B.

doi:10.1016/j.mssp.2011.08.005

Cited by 10 publications

(5 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Like Fe, 21 experimentally observed gettering behaviors of Cr, 27 and Co 28 show a very rapid drop of gettered metal concentration as phosphorus concentration decreases, suggesting a strongly super-linear relationship between phosphorus and gettered metal concentrations. Ref.…”

Section: Continuum Models For P Deactivation and Fe Getteringmentioning

confidence: 91%

Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

Chen¹,

Trzynadlowski²,

Dunham³

2014

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inDissolving, trapping and detrapping mechanisms of hydrogen in bcc and fcc transition metals AIP Advances 3, 012118 (2013); 10.1063/1.4789547 Atomic diffusion bonding of wafers with thin nanocrystalline metal films J. Vac. Sci. Technol. B 28, 706 (2010); 10.1116/1.3437515 Molecular simulation on interfacial structure and gettering efficiency of direct silicon bonded (110)/(100) substrates

show abstract

Section: Continuum Models For P Deactivation and Fe Getteringmentioning

confidence: 91%

Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

Chen¹,

Trzynadlowski²,

Dunham³

2014

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…It is plausible that chromium point defects are largely responsible for the initially low lifetime and dramatic lifetime improvement. Chromium is known to be recombination-active in n-type silicon [4] and has sufficient diffusivity and solubility to be gettered [37]. We acknowledge the possibility that small copper-, nickel-, and/or iron-silicide precipitates may also contribute, because despite low recombination activity of isolated point defects in n-type silicon, these species readily form recombination-active precipitates [39] but respond well to extended gettering [40][41][42].…”

Section: Impurity Concentrations Are At or Below The Detection Limit mentioning

confidence: 96%

“…The EXT process consists of the same plateau at 845°C followed by a 2 hr anneal at 650°C before unloading. The EXT process was inspired by experience with the successful extraction of interstitial iron from p-type materials [35,36], but tuned for the extraction of chromium following the guidance of reference [37]. Iron point defects are not expected to significantly reduce lifetime in n-type silicon, while chromium point defects are expected to remain recombination active in n-type silicon, because of the ratio of hole and electron capture cross sections [4].…”

Section: Passivation Involved Formation Of a 20 Nm Layer Of Al 2 O 3 mentioning

confidence: 99%

Minority-carrier lifetime and defect content of n-type silicon grown by the noncontact crucible method

Kivambe

Powell

Castellanos

et al. 2014

Journal of Crystal Growth

View full text Add to dashboard Cite

We evaluate minority-carrier lifetime and defect content of n-type photovoltaic silicon grown by the noncontact crucible method (NCC-Si). Although bulk impurity concentrations are measured by inductively coupled plasma mass spectroscopy to be less than one part per million, homogeneously throughout the as-grown material we observe lifetimes in the ~150 µs range, well below the theoretical entitlement of single-crystalline silicon. These observations suggest the presence of homogeneously distributed recombination-active point defects. We compare an industry-standard gettering profile to an extended gettering profile tailored for chromium extraction, to elucidate potential gains and limitations of impurity gettering. Near the ingot top, gettering improves lifetimes to 750 and >1800 µs for standard and extended profiles, respectively. Relatively lower gettered lifetimes are observed in wafers extracted from the ingot middle and bottom. In these regions, concentric-swirl patterns of low lifetime are revealed after gettering. We hypothesize that gettering removes a large fraction of fast-diffusing recombination-active impurities, while swirl microdefect regions reminiscent of Czochralski silicon can locally limit gettering efficiency and lifetime. Apart from these swirl microdefects, a low dislocation density of <10 3 cm-2 is observed. The millisecond lifetimes and low dislocation density suggest that, by applying appropriate bulk microdefect and impurity control during growth and/or gettering, n-type NCC-Si can readily support solar cells with efficiencies >23%.

show abstract

“…because it strongly reduces the carrier lifetime of crystalline silicon wafer at a relatively high concentration of about 5 × 10 14 cm −3 , as measured by SIMS in an earlier study [9].…”

Section: Introductionmentioning

confidence: 60%

Optimized Temperature in Phosphorous Diffusion Gettering Setup of Chromium Transition Metal in Solar Grade Multicrystalline p-Type Silicon Wafer

2016

View full text Add to dashboard Cite

We have investigated in this work the effect of the temperature profile during homogeneous phosphorous diffusion gettering (PDG) on multicrystalline (mc-Si) silicon p-type wafers destined for photovoltaic solar cells. Temperatures were varied from 800 • C due probably to a partial dissolution of the metallic precipitates, especially at the grain boundaries and in the dislocations vicinity. The related τCr-Impurity lifetime value of about 8.5 µs is extracted, which is the result of interstitial Cri or CriBs pairs, proving their strongest recombination activity in silicon.

show abstract

Effect of extended phosphorus diffusion gettering on chromium impurity in HEM multicrystalline silicon

Cited by 10 publications

References 22 publications

Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

Minority-carrier lifetime and defect content of n-type silicon grown by the noncontact crucible method

Optimized Temperature in Phosphorous Diffusion Gettering Setup of Chromium Transition Metal in Solar Grade Multicrystalline p-Type Silicon Wafer

Contact Info

Product

Resources

About