The chemical factor and its influence on the formation of defect structures and their gettering properties in layers of silicon implanted with chemical-active ions

Алешин, А. Н.; Enisherlova, K. L.; Калинин, А. А.; Mordkovich, V.N.

doi:10.1016/0168-583x(95)01247-8

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…However as was shown in [6] to achieve gettering by implanting solely carbon ions it is needed to employ high energy process (of the order of MeV) with a large dose of implantation (a dose of 10 16 1/cm 2 ) which complicates the technology. As shown earlier [7,8] implantation of two impurities (oxygen and carbon) at low doses may be more efficient since the presence of strong chemical bond between these impurities changes phase formation processes in ion doped layers.…”

Section: Introductionmentioning

confidence: 89%

Physicochemical fundamentals of phase formation in silicon layers implanted with oxygen and carbon

Алешин¹,

Enisherlova²

2019

MoEM

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The thermodynamic and kinetic regularities of processes occurring during heat treatment in silicon layers implanted with oxygen and carbon ions have been considered. We have analyzed the regularities of silicon deformation, impurity distribution and defect formation after different annealing modes. Diffusion smearing of implanted impurities in these layers has not been observed during carbon and oxygen implantation. As-annealed carbon does not occupy sites of the silicon lattice, in contrast to the implantation behavior of other impurities, e.g. boron and phosphorus. Phase formation regularities in implanted layers during subsequent heat treatment have been analyzed. Changes in the free energy of the system during heterogeneous and homogeneous precipitate nucleation have been compared. Sequential implantation with carbon and oxygen ions has been found to initiate diffusion flows of carbon and oxygen toward the center of the ion doped layer (the uphill diffusion phenomenon). The possibility of uphill diffusion has been analyzed from the standpoints of the Onsager theory. We show that the contribution of the chemical interaction between oxygen and carbon is far greater than the entropy contribution to the diffusion flux. We have demonstrated the high efficiency of ion doping with oxygen and carbon for gettering of uncontrolled impurities from active regions of silicon structures. The efficiency of this gettering process has been assessed for epitaxial structures in which layers had been grown on silicon wafers implanted with these impurities. Uphill diffusion in the layers after double doping with carbon and oxygen has led to the formation of more defects which may provide for efficient gettering. We have found the optimal oxygen and carbon implantation dose ratio for maximal gettering efficiency.

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Section: Introductionmentioning

confidence: 89%

Physicochemical fundamentals of phase formation in silicon layers implanted with oxygen and carbon

Алешин¹,

Enisherlova²

2019

MoEM

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“…Therefore a special process has been developed for introducing the required oxygen concentration into zone melting grown silicon wafers by ion implantation. It has been reported [19] that the efficiency of impurity precipitate/dislocation agglomerate formation increases considerably if carbon atoms are preliminarily implanted into silicon wafers.…”

Section: Intrinsic Gettersmentioning

confidence: 99%

Getters in silicon

Харченко¹

2019

MoEM

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Gettering of rapidly diffusing metallic impurities and structural defects in silicon which is the main material for IC fabrication, high-power high-voltage devices and neutron doped silicon has been studied. Structural defect based getters and gas phase getters based on chlorine containing compounds have been analyzed. Formation of structural defect based getters requires producing intrinsic sources of dislocation generation and precipitate/dislocation agglomerate formation. We show that dislocations are generated at microcrack mouths and form a low-mobility dislocation network at inactive wafer sides. In the latter case the defects are generated in the wafer region adjacent to the active layer of the electronic component. The generation of intrinsic getters is based on the decomposition of the supersaturated oxygen solid solution in silicon which favors the formation of a complex defect system in silicon that consists of various precipitate/dislocation agglomerates. Stacking faults also form, i.e., oxide precipitates with Frank’s dislocation loop clouds. Two intrinsic getter formation methods have been considered: one is related to oxygen impurity drain from the wafer surface region and the other implies accurate control of vacancy distribution over wafer thickness. We have analyzed the effect of getters as defect structures on the reduction of the mechanical stress required for dislocation generation onset which may eventually determine the mechanical strength of silicon wafers. The mechanism of impurity and defect gettering by gas phase medium with chlorine-containing compound additions has been considered. We show that silicon atom interaction with chlorine in the surface wafer region at high temperatures may cause the formation of vacancies which may penetrate to the specimen bulk with some probability. This leads to the case ∆Сv > 0 and ∆Ci ≤ 0, which changes the composition and density of the microdefects. Examples have been given for practical use of heat treatment of silicon wafers in a chlorine-containing atmosphere during oxide film application with the aim to dissolve microdefects, drain rapidly diffusing impurities from crystal bulk and prevent the formation of generation/recombination centers during device fabrication and silicon neutron doping.

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“…Поэтому для пластин кремния, выращенного методом БЗП разработана технология введения требуемой концентрации кислорода с использованием ионной имплантации. В частности, в работе [19] показано, что эффективность образования примесных преципитат−дислокационных скоплений значительно возрастает, если предварительно в пластины кремния имплантировать атомы углерода.…”

Section: геттеры на основе дефектов структурыunclassified

The getters in silicon

Харченко

2019

Izv. vysš. učebn. zaved., Mater. èlektron. teh.

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The processes of gettering of fast-diffusing metal impurities and structure defects in silicon, mainly used in the production of integrated circuits, power high-voltage devices, nuclear-doped silicon, are considered. The getters based on structural defects and gas-phase getters based on chlorine-containing compounds are analyzed. It is noted that for the formation of getters on the basis of structural defects, it is necessary to create internal sources for generation of dislocations and formation of precipitate — dislocation clusters. It is shown that dislocations are generated in the mouths of microfractures, which then form a sedentary dislocation grid on the non-working side of the plates. In the second case, defects are created in the area of the plate adjacent to the active layer of the electronic component. The process of creating an internal getter is based on the decomposition of a supersaturated solid oxygen solution in silicon, due to which a complex defect medium consisting of various precipitate-dislocation clusters is formed in the crystal. The packing defect as oxide precipitate with a cloud of Frank’s loops is formed. Two variants of creating an internal getter are considered — first is associated with the distillation of an oxygen impurity from the near-surface region of the plate, the second is associated with a fine adjustment of the distribution of vacancies along the plate thickness. The analysis of the influence of the getter as the defect structure reducing the magnitude of mechanical stress of the beginning of the generation of dislocations, which ultimately can determine the mechanical strength of the silicon wafer.This paper also considers the mechanism of gas-phase medium impurities and defects gettering with the addition of chlorine-containing compounds. It is shown that at elevated temperatures, due to the interaction of silicon atoms with chlorine in the near-surface region of the plate, it is possible to create vacancies that penetrate the sample volume with some probability. As a result, the case DСv > 0, DCi £ 0 is realized, that leads to a change in the composition of microdefects and their density. The examples of practical application of heat treatment in chlorine-containing atmosphere silicon wafer during application of the oxide film, in the case of the target the need for dissolution of the microdefects and of the withdrawal of fast diffusing impurities from the crystal volume, and to prevent the formation of generation-recombination centers in the manufacturing process of devices and in a nuclear doping silicon.

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The chemical factor and its influence on the formation of defect structures and their gettering properties in layers of silicon implanted with chemical-active ions

Cited by 3 publications

References 5 publications

Physicochemical fundamentals of phase formation in silicon layers implanted with oxygen and carbon

Physicochemical fundamentals of phase formation in silicon layers implanted with oxygen and carbon

Getters in silicon

The getters in silicon

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