Oxidation-induced Stacking Faults In Silicon Research Articles

Optical characterization of deep states associated with oxidation-induced stacking faults in silicon

Abstract We have studied the effect of sub-band gap radiation on the defects associated with the Frank partial dislocation (Burgers vector a /3(111)) bounding oxidation-induced stacking faults (OISF) in n-type silicon. We have observed the contrast produced using IR-beam-induced current (IRBIC) and have studied the effect of the modification of the contrast of individual dislocations with below band gap radiation by quenched IR-beam-induced current (QIRBIC). We have compared these spectra with absolute measurements of the photocapacitance cross-section of the dominant deep state associated with the Frank partials. QIRBIC spectra for “clean”, gold-decorated and two levels of copper-decorated samples have been measured. A model of the recombination kinetics is discussed.

Light-beam-induced transient spectroscopy of oxidation-induced stacking faults in silicon

Abstract We have applied the technique of light-beam-induced transient spectroscopy, which characterizes minority carrier capture and emission at point and extended defects, to oxidation-induced stacking faults in n-type silicon. We have compared the minority carrier trap data with conventional deep-level transient spectra for majority carrier traps. We find that we are able to distinguish between hole capture at randomly distributed point defects (e.g Au), and hole capture at point defects which are associated with the extended-defect strain field.

Thermal wave imaging of misfit dislocations and correlation with minority carrier lifetime

It has recently been demonstrated that oxidation-induced stacking faults in silicon can be imaged in a non-contact manner using a modulated optical reflectance method associated with the propagation of thermal waves and plasma waves in the material. We applied the high spatial resolution capability of this imaging technique to the observation of epitaxial misfit dislocations at the interfaces of a layer of germanium-doped silicon buried within a silicon structure. The samples were angle-lapped and polished to allow the inspection over the whole depth of the structure. The misfit dislocation images dramatically demonstrate the capability of the technique for the detection of defects beneath the silicon surface. The minority carrier lifetime of such structures, which has been determined previously using a depth-dependent technique, is correlated with the intensity of the modulated optical reflectance signal. Using a stack of epitaxial Si/Si(Ge) layers with various Ge concentrations, the modulated optical reflectance is shown to be proportional to the concentration of germanium.

Fast shrinkage of oxidation-induced stacking faults in silicon at the initial stage of annealing in nitrogen

The shrinkage of oxidation-induced stacking faults (OSF′s) in silicon has been studied in the temperature range of 950–1100 °C in nitrogen ambient. Abnormally fast OSF shrinkage with activation energy of 2.3 eV has been observed at the initial stage of annealing. This fast shrinkage regime becomes more pronounced as the annealing temperature is reduced. It is proposed that the fast OSF shrinkage rate is due to the fact that initially the shrinkage is dominated by the rate of self-interstitial capture at the silicon/silicon dioxide interface, while the subsequent lower rate with activation energy of 4.3 eV is due to the traditionally accepted diffusion-limited mechanism. Because of the difference in activation energies, as temperature increases above about 1100 °C the latter mechanism becomes dominant and the fast shrinkage regime disappears.

Effects of Cl+ and F+ implantation of oxidation-induced stacking faults in silicon

Three implantation effects were investigated in floating-zone-grown silicon: (a) the effect of Cl+ implantation resulting in the shrinkage of oxidation-induced stacking faults; (b) the effect of F+ implantation giving rise to defaulting of the 1/3[111] Frank dislocations into 1/2[110] perfect dislocations due to the interaction with 1/6[112̄] Shockley partials; (c) the effect of a combined F+ and Cl+ implantation of dislocation motion. Notwithstanding the limited magnification of double-crystal x-ray topography it proves to be a valuable technique for determination of the effects of implantation, as removal of F; the oxidation layer is unnecessary for observation of the oxidation-induced stacking faults. Moreover, the role of the oxide layer in the Si-SiO2 interface can be followed more appropriately.

Laser-enhanced nucleation of oxidation-induced stacking faults in silicon

We have studied the laser-enhanced nucleation of oxidation-induced stacking faults in ion-implanted silicon. Silicon ions of 100 keV were implanted onto the silicon surface in the dosages ranging from 1.0×1013 to 1.0×1014 cm−2. The laser beam used was 1.06 μm in wavelength with a diameter of 40 μm, and was generated from a Q-switched Nd:YAG laser at a repetition rate of 12 kHz and a 150-ns pulse width. It was found that the laser irradiation enhanced the generation of oxidation-induced stacking faults or their generation nuclei through the implantation-induced lattice defects at the boundary between the laser scanned and nonscanned regions. Laser-enhanced nucleation is caused by the supersaturation of the silicon self-interstitials generated by the rapid heating-cooling cycle induced by laser irradiation reacting with the self-interstitials induced during oxidation.

Oxidation-enhanced or retarded diffusion and the growth or shrinkage of oxidation-induced stacking faults in silicon

An analysis of the conditions for obtaining oxidation-enhanced or retarded dopant diffusions (OED or ORD), in accordance with the stacking fault growth/shrinkage phenomena, is carried out for the oxidation of Si by assuming that vacancy and Si self-interstitials coexist at high temperatures and that during oxidation a local equilibrium of point defects is attained. It is shown that the Sb ORD data can be explained quantitatively. Under most oxidation conditions the SiO2-Si interface acts as a source of Si self-interstitials, but at sufficiently high temperatures and long oxidation times the SiO2-Si interface behaves as a sink for Si self-interstitials (or equivalently as a source of vacancies). We suggest a model for this sink behavior in terms of the formation of SiO molecules at the interface and of their subsequent diffusion into the SiO2 film.

Preoxidation gettering of oxidation-induced stacking faults in silicon by the phosphorus diffusion process: J-H. Chen and M-C. Chen Int. J. Electron. 47(6), 555 (1979)

Preoxidation gettering of oxidation-induced stacking faults in silicon by the phosphorus diffusion process: J-H. Chen and M-C. Chen Int. J. Electron. 47(6), 555 (1979)

Growth kinetics of oxidation-induced stacking faults in silicon: A new concept

It is reasonable to assume that the volume increase of about 120% associated with the formation of a SiO2 molecule from a Si atom during thermal oxidation of Si is facilitated by viscoelastic flow of the newly formed SiO2 layer at the SiO2-Si interface. This flow is driven by a compressive plane stress. We propose that it is this stress which gives rise to a supersaturation of Si self-interstitials in the Si crystal, and that consequently the growth kinetics of oxidation-induced stacking faults is determined by the kinetics of the viscoelastic flow of the SiO2.

Scanning Electron Microscopic Observation of Oxidation-Induced Stacking Faults in Silicon

An electron beam induced current (EBIC) method using an Al-Si Schottky barrier has been developed and applied to the observation of oxidation-induced stacking faults in (001) silicon. The minority carriers in thermally-oxidized silicon have a very large diffusion length. Analysis of the Y-modulation image of a stacking fault is effective for correlating the EBIC image contrast with the induced-current variation. Increasing beam energy increases the depth of a Frank partial dislocation segment showing the maximum contrast. A deep dislocation segment shows a larger resolution than a shallow one, and a further increase in resolution results from an increase in the beam energy. The Schottky barrier method is applied to the evaluation of the electrical activity of stacking faults and to the examination of their annealing behavior.

Role of point defects in the growth of the oxidation-induced stacking faults in silicon. II. Retrogrowth, effect of HCl oxidation and orientation

Role of point defects in the growth of the oxidation-induced stacking faults in silicon. II. Retrogrowth, effect of HCl oxidation and orientation

TCE oxidation for the elimination of oxidation-induced stacking faults in silicon: T. Hattori. Solid-St. Technol. p. 85 (November 1979)

TCE oxidation for the elimination of oxidation-induced stacking faults in silicon: T. Hattori. Solid-St. Technol. p. 85 (November 1979)

Preoxidation gettering of oxidation-induced stacking faults in silicon by the phosphorus diffusion process : Jhy-Horng Chen and Mao-Chieh Chen. Int. J. Electron.47, (6) 555 (1979)

Preoxidation gettering of oxidation-induced stacking faults in silicon by the phosphorus diffusion process : Jhy-Horng Chen and Mao-Chieh Chen. Int. J. Electron.47, (6) 555 (1979)

Preoxidation gettering of oxidation-induced stacking faults in silicon by the phosphorus diffusion process

Preoxidation gettering of oxidation-induced stacking faults (OSF) in a silicon wafer by the reverse side phosphorus diffusion-induced misfit dislocations has boon studied. This gettering scheme either prevents the formation of OSF during the thermal oxidation of silicon or deactivates the electrical activity of those OSF having heen formed. The get taring action takes place by removing or isolating the impurities from being precipitated at the OSF nueleation sites and confines them to the misfit dislocations al the reverse.side of the wafer. It is expected that the misfit dislocations continue to act as sinks of impurities during the subsequent high-temperature oxidation process and results in a great improvement of device yield and performance.

The influence of annealing ambient on the shrinkage kinetics of oxidation-induced stacking faults in silicon

The shrinkage behavior of oxidation-induced stacking faults (OSF’s) during an annealing in nitrogen, argon, and hydrogen is studied as a function of both annealing temperature and time. Independent of the used gas atmosphere, the OSF shrinkage rate is characterized by an activation energy of 4.9 eV. To explain the different experimental results, an interstitial model for the stacking fault shrinkage is proposed.

Oxygen partial pressure dependence of the fixed surface-state charge QSS due to thermal oxidation of n- (100) silicon

The fixed surface-state charge QSS has been determined for (100) n-type silicon oxidized in different partial pressures of oxygen (pO2). It has been found that the QSS is directly proportional to pO2 and is given by QSS×10−10= (14.1±12.7) pO2+(5.44±0.78) in the pO2 range 0.1–1.0 where pO2 is the partial pressure of oxygen in the oxygen-nitrogen mixture. The results are discussed in view of the concentration of the excess silicon present in silicon near the oxide-silicon interface and its assumed relationship to the length of oxidation-induced stacking faults in silicon.

Control of Oxidation-Induced Stacking Faults in Silicon by Chlorine Implantation

Stacking faults in thermally-oxidized silicon wafers were shrunk by chlorine implantation into the SiO2 layer and subsequent annealing in dry O2. By assuming that the shrinkage of stacking faults was due to vacancy diffusion into them, the vacancy concentration near the Si–SiO2 interface was estimated from the observed shrinkage rates. The increase in vacancy concentration due to chlorine was expressed as κCn at 1100°–1200°C, where κ is a factor dependent on the Cl content, and Cn is the vacancy concentration in equilibrium with the oxidizing interface of non-implanted wafers. Chlorine showed no effect on fault shrinkage during annealing in dry N2. Chlorine implantation into the substrates of oxidized wafers and into bare Si wafers caused unfaulting reaction of stacking faults, suppression of fault generation, and generation of secondary defects during subsequent annealing in dry O2.

Erratum: Role of point defects in the growth of the oxidation-induced stacking faults in silicon

Erratum: Role of point defects in the growth of the oxidation-induced stacking faults in silicon

Role of point defects in the growth of the oxidation-induced stacking faults in silicon

A new mechanism, describing the growth of the oxidation-induced stacking faults (OISF) in silicon has been formulated. This mechanism predicts the temperature, time, and oxygen-pressure dependences of the length of the faults in agreement with experimental measurements. The formulation of the mechanism and the derivation of an equation for the length is based on the following assumptions. (a) The growth of the stacking faults at the heterogeneous nucleation sites is analogous to the crystalline growth at the surface kinks. (b) There is an excess of silicon atoms at the Si${\mathrm{O}}_{2}$-Si interface. The concentration of the excess silicon atoms depends on the partial pressure of oxygen during oxidation and on the concentration of the charged vacancies in the adjacent bulk of the silicon. (c) The self-diffusion in silicon occurs by the formation and migration of the charged vacancies. The resultant derivation and comparison with experiment strongly support the new mechanism. (i) The equation describing the length of OISF has been derived to be $L={K}^{\ensuremath{'}}{P}_{{\mathrm{O}}_{2}}^{m}{t}^{n}\mathrm{exp}(\ensuremath{-}\frac{Q}{\mathrm{kT}})$, which is exactly the same as borne out of experimental findings reported earlier. (ii) Values of $m$ and $n$ have been derived and were found to be in good agreement with previously measured values. (iii) Expressions for ${K}^{\ensuremath{'}}$ and $Q$ have been obtained. Using these expressions and available data from literature, ${K}^{\ensuremath{'}}$ and $Q$ were calculated and were found to be in excellent agreement with experiment. (iv) Two different sets of values of $m$, ${K}^{\ensuremath{'}}$ and $Q$ for lower and higher temperature ranges have been obtained. This is in agreement with experimental observation which clearly indicated existence of two temperature ranges (one \ensuremath{\le} 1150\ifmmode^\circ\else\textdegree\fi{}C and the other \ensuremath{\ge} 1200\ifmmode^\circ\else\textdegree\fi{}C).

Reflection X-ray topography of oxidation-induced stacking faults in silicon

Reflection X-ray topography of oxidation-induced stacking faults in silicon