Self‐ and impurity diffusion in Ge and Si

Shaw, D.

doi:10.1002/pssb.2220720102

Cited by 115 publications

(34 citation statements)

References 43 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result agrees well with direct calculations of the equilibrium coefficient for reaction [3] (41). D vs. n.--The general expression for the diffusion coefficient of P in Si can be written as (43) 1, and 2 and r-= 0, --, and --. Equation [7] arises because the concentration of vacancies in the rth charge state is (from mass action effects) --…”

Section: Analysis Of Resultssupporting

confidence: 88%

A Quantitative Model for the Diffusion of Phosphorus in Silicon and the Emitter Dip Effect

Fair¹,

Tsai²

1977

J. Electrochem. Soc.

325

View full text Add to dashboard Cite

A consistent model of P diffusion in Si is presented which accounts quantitatively for the existence of electrically inactive P, the "kink" and the tail regions of the P profile, and the emitter dip effect. In this model it is shown that three intrinsic P diffusion coefficients exist, each one associated with the diffusion of P with vacancies in three different charge states. In the so-called "anomalous" high concentration region of the profile (n ~ 10 2~ cm-a), it is shown that equilibrium concentration of P+V = pairs dominates P diffusion and P electrical activity. At lower electron concentrations when the Fermi level is ,~0.11 eV below the conduction band, the V = vacancy gives up an electron, and the 0.3 eV lower binding energy of the resulting P+V-pairs enhances the probability for pair dissociation by a factor of 10-35, depending on the temperature. This effect creates a steady-state excess concentration of Vvacancies which flow away from the point of pair dissociation. The concentration of excess V-vacancies created is proportional to the number of P +V = pairs created at the Si surface times the enhanced probability for pair dissociation. These vacancies in the V-charge state interact with P to create the enhanced tail diffusion. In a npn structure, the charge state of the excess vacancies becomes V + in the base region, thus enhancing the diffusivity of the base dopant and causing the emitter dip effect. The magnitude by which the P tail diffusivity and the base dopant diffusivity are enhanced is the same and may reach a factor of 135 for a 900~ diffusion.At high concentrations the diffusion of phosphorus (P) into silicon (St) produces an impurity atom distribution that differs considerably from the Gaussian or complementary error-function distributions (I-7). Numerous models have been proposed to explain this anomalous deviation from simple diffusion theory. Lawrence (8) suggested that the retardation of P diffusion was a result of the precipitation of P at moving dislocations. Dash and Joshi similarly postulated that the onset of anomalous P diffusion occurred simultaneously with the generation of dislocations in the Si lattice, at a critical integrated P concentration (9). However, the recent results of Sato et al. (10) disagree with this model, and Duffy et al. (11) found no evidence of dislocations or precipitation following the predeposition of prominently kinked P profiles. Significant numbers of dislocations and accompanying preCipitation occur only after the drive-in cycle (11).Other P diffusion models include the saturated lattice site model of Bakeman and Borrego (12), the thin surface barrier model of Makris et al. (13), impurity band effects on the electron activity coefficient (10, 14), the existence of a molten Si-P phase to explain the apparent flattened region of the P profile (15), and That's model of enhanced diffusion due to plastic deformation and subsequent generation of excess vacancies (16, 17). All of the above models have been criticized by Hu in a recent review (18), and so ad...

show abstract

Section: Analysis Of Resultssupporting

confidence: 88%

A Quantitative Model for the Diffusion of Phosphorus in Silicon and the Emitter Dip Effect

Fair¹,

Tsai²

1977

J. Electrochem. Soc.

325

View full text Add to dashboard Cite

show abstract

“…Studies on Cu precipitation in Ge and on thermally induced acceptors formed after quenching reveal a V formation enthalpy of about 2 eV. 24,[67][68][69] Metal diffusion studies of Giese et al 25 support the results of the former quenching experiments. Recently, Vanhellemont et al 26 report a best estimate of (2.35 6 0.1) eV and (0.6 6 0.1) eV for the formation and migration enthalpy of V, respectively, which is based on available experimental and theoretical results.…”

Section: Thermodynamic Propertiesmentioning

confidence: 65%

Diffusion ofn-type dopants in germanium

Chroneos¹,

Bracht²

2014

Applied Physics Reviews

163

114

View full text Add to dashboard Cite

“…Pinto [30] suggests that, similar to the silicon vacancy [44], the high-temperature vacancy in Ge differs in properties from the low-temperature one. Taking into account that the MD simulations estimate neutral vacancy properties, and that the quenching experiments measure the concentration of a single-charged negative vacancy [21,45,46], and implementing the method proposed by Kro¨ger [46], one can estimate the formation energy of the neutral vacancy as suggested by Shaw [45], as follows.…”

Section: Experimental Values Of the Migration And Formation Energy Ofmentioning

confidence: 99%

“…All simulations shown in Table 2 were indeed performed assuming uncharged point defects. In most experiments, however, it cannot be excluded that part of the point defects that are measured are in a charged state as is the case for vacancies [45].…”

Section: The Formation and Migration Energy Of The Selfinterstitialmentioning

confidence: 99%