Defects related to electrical doping of 4H-SiC by ion implantation

Nipoti, Roberta; Ayedh, Hussein M.; Svensson, B. G.

doi:10.1016/j.mssp.2017.10.021

Cited by 26 publications

(16 citation statements)

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“…These deep levels caused by compensating impurities were identified as lifetime killers, such as the Z1/2 and EH6/7 centers [11][12][13]. Despite several experimental studies on discovering the implantationinduced defects and electrical activation [14][15][16], there are several incongruences on the enhancement of electrical activation. For instance, Nipoti et al [14,15,17] indicated that the activation (i.e., implanted ions occupy the targeted lattice sites) of p-type 4H-SiC can be enhanced by increasing the Al-implanted concentration whereas Saks et al [16] claimed the decrease of activation rate is due to the saturation of dopants in SiC at high doping levels.…”

Section: Introductionmentioning

confidence: 99%

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

Liu

et al. 2021

J. Mater. Chem. C

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Section: Introductionmentioning

confidence: 99%

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

Liu

et al. 2021

J. Mater. Chem. C

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“…The results give useful indications for the fabrication of 4H-SiC JBS and MOSFETs.The main dopant species for SiC are Nitrogen (N) and Phosphorous (P) for n-type doping, and Aluminum (Al) for p-type doping. High post-implantation annealing temperatures (> 1500°C) are typically required to bring these species in substitutional positions and achieve their electrical activation [5,6,7]. In particular, selectively doped p-type regions are key parts of both JBS and MOSFETs and the control of their electrical properties has a significant impact on several devices parameters (e.g., Ohmic contacts formation, device on-resistance, threshold voltage and channel mobility, etc.…”

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confidence: 99%

Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers

Spera

Corso

Franco

et al. 2019

Materials Science in Semiconductor Processing

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This work reports on the effect of high temperature annealing on the electrical properties of p-type implanted 4H-SiC. Ion implantations of Aluminium (Al) at different energies (30 -200 keV) were carried out to achieve 300 nm thick acceptor box profiles with a concentration of about 10 20 at/cm 3 . The implanted samples were annealed at high temperatures (1675-1825 °C). Morphological analyses of the annealed samples revealed only a slight increase of the surface roughness RMS up to 1775°C, while this increase becomes more significant at 1825°C (RMS=1.2nm). Room temperature Hall measurements resulted in a hole concentration in the range 0.65-1.34×10 18 /cm 3 and mobility values in the order of 21-27 cm 2 V -1 s -1 . The temperature dependent electrical measurements allowed to estimate an activation energy of the Al-implanted specie of about 110 meV (for the post-implantation annealing at 1675°C) and a fraction of active p-type Al-dopant ranging between 39% and 56%. The results give useful indications for the fabrication of 4H-SiC JBS and MOSFETs.The main dopant species for SiC are Nitrogen (N) and Phosphorous (P) for n-type doping, and Aluminum (Al) for p-type doping. High post-implantation annealing temperatures (> 1500°C) are typically required to bring these species in substitutional positions and achieve their electrical activation [5,6,7]. In particular, selectively doped p-type regions are key parts of both JBS and MOSFETs and the control of their electrical properties has a significant impact on several devices parameters (e.g., Ohmic contacts formation, device on-resistance, threshold voltage and channel mobility, etc.).Hence, understanding the dependence of the properties of p-type implanted layers on the activation annealing temperature is very important for device manufacturers to set the right process for the optimal device characteristics. In this context, although several investigations reported on the properties of Al-implanted 4H-SiC layers [8,9,10], the large variety of experimental conditions and the evolution of the annealing procedures always make this topic open to scientific discussions.Hall-effect measurements are often used to study the electrical properties of p-type 4H-SiC layers, in order to determine key parameters like the holes concentration and mobility [11]. A critical issue of this methodology is the choice of the Hall scattering factor rH for SiC [12,13]. In fact, the difficulty to extract the mobility and the free hole concentration from Hall measurements is related to the correct knowledge of rH. However, many authors often interpret the experimental Hall results on p-type 4H-SiC assuming rH=1, which in turn leads to an overestimation of the doping level in the material [9,14]. Only few works specifically reported experimental calculations of the Hall scattering factor rH for SiC [15,16], whose findings should be considered for a correct analysis of the currently available data.This paper reports on the morphological and electrical properties of p-type implanted 4H-SiC annealed...

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“…The intensity value of the band–band peak is equal to that of the sample subjected to annealing for 1 h at 1650 °C (see Figure 3b). Thermally annealed samples exhibit a large peak centred at 490 nm with 175 nm full width at half maximum (FWHM), which can be related to the generation of a high defectiveness concentration and in particular to Vc generated in the implanted region and in the epitaxial layers [11,12]. In addition, interstitial aggregates present within the implanted layers provide an emission contribution to wavelengths corresponding to intra-band-gap emission signal.…”

Section: Resultsmentioning

confidence: 99%

Laser Annealing of P and Al Implanted 4H-SiC Epitaxial Layers

et al. 2019

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This work describes the development of a new method for ion implantation induced crystal damage recovery using multiple XeCl (308 nm) laser pulses with a duration of 30 ns. Experimental activity was carried on single phosphorus (P) as well as double phosphorus and aluminum (Al) implanted 4H-SiC epitaxial layers. Samples were then characterized through micro-Raman spectroscopy, Photoluminescence (PL) and Transmission Electron Microscopy (TEM) and results were compared with those coming from P implanted thermally annealed samples at 1650–1700–1750 °C for 1 h as well as P and Al implanted samples annealed at 1650 °C for 30 min. The activity outcome shows that laser annealing allows to achieve full crystal recovery in the energy density range between 0.50 and 0.60 J/cm2. Moreover, laser treated crystal shows an almost stress-free lattice with respect to thermally annealed samples that are characterized by high point and extended defects concentration. Laser annealing process, instead, allows to strongly reduce carbon vacancy (VC) concentration in the implanted area and to avoid intra-bandgap carrier recombination centres. Implanted area was almost preserved, except for some surface oxidation processes due to oxygen leakage inside the testing chamber. However, the results of this experimental activity gives way to laser annealing process viability for damage recovery and dopant activation inside the implanted area.

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Defects related to electrical doping of 4H-SiC by ion implantation

Cited by 26 publications

References 55 publications

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers

Laser Annealing of P and Al Implanted 4H-SiC Epitaxial Layers

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Defects related to electrical doping of 4H-SiC by ion implantation

Cited by 26 publications

References 55 publications

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

MD simulation study on defect evolution and doping efficiency of p-type doping of 3C-SiC by Al ion implantation with subsequent annealing

Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers

Laser Annealing of P and Al Implanted 4H-SiC Epitaxial Layers

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Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers