Showing papers on "Dopant Activation published in 2023"
TL;DR: In this paper , the impact of fluorine co-doping on the formation of a highly activated N-type shallow junction in germanium (Ge) was investigated by employing a 355 nm nanosecond ultraviolet laser annealing.
Abstract:
By employing a 355 nm nanosecond ultraviolet laser annealing, the impact of fluorine (F) co-doping on the formation of a highly activated N-type shallow junction in germanium (Ge) was investigated. Secondary ion mass spectrometry depth profiling of phosphorus (P) demonstrated that an ultra high P concentration of 9e20/cm3 at a shallow junction of 55 nm with less dopant diffusion can be obtained using ns laser annealing. F co-doping was confirmed to be an efficient way to improve the activation of the P dopants, but show less influence on the redistribution of P dopants within the NLA melted region. However, the activation level of the shallow junction could be increased to approximately 1e20/cm3 in the presence of F at an optimized concentration.
TL;DR: In this paper , GaAs TJs with Si and Te delta-doping were grown via solid source molecular beam epitaxy to investigate the tunneling performance and thermal stability, while Si δ-doped TJs exhibited typical tunneling characteristics with an Esaki peak current density of 173 A/cm2.
Abstract: Tunnel junctions (TJs) are essential for high-performance multijunction solar cells to act as transparent low resistance paths for carriers to travel between adjacent cells. However, TJs typically exhibit highly degraded tunneling performance due to unwanted dopant out-diffusion during top cell growth. In this study, GaAs TJs with Si and Te delta-doping (δ-doping) were grown via solid source molecular beam epitaxy to investigate the tunneling performance and thermal stability. While Si δ-doped TJs exhibited typical tunneling characteristics with an Esaki peak current density of 173 A/cm2, Te δ-doped TJs revealed 1.5 A/cm2 at Vbias = 100 mV without negative resistance. It was found that the performance degradation after annealing at 600 °C for 90 min was significantly higher for TJs with Si δ-doping than for Te. Secondary ion mass spectroscopy measurements reveal that Te shows no clear signs of dopant diffusion while Si exhibited significant out-diffusion in the active TJ layer after thermal annealing. The superior thermal stability of Te compared to Si proves to be advantageous as an alternative n-type dopant for high temperature and long duration grown multi-junction solar cells.
TL;DR: In this article , the influence of laser thermal annealing on dopant activation was investigated, and it was shown that large LTA energy density leads to tightening threshold voltage and sub-threshold swing distribution.
Abstract: The bit density is generally increased by stacking more layers in 3D NAND Flash. Lowering dopant activation of select transistors results from complex integrated processes. To improve channel dopant activation, the test structure of vertical channel transistors was used to investigate the influence of laser thermal annealing on dopant activation. The activation of channel doping by different thermal annealing methods was compared. The laser thermal annealing enhanced the channel activation rate by at least 23% more than limited temperature rapid thermal annealing. We then comprehensively explore the laser thermal annealing energy density on the influence of Poly-Si grain size and device performance. A clear correlation between grain size mean and grain size sigma, large grain size mean and sigma with large laser thermal annealing energy density. Large laser thermal annealing energy density leads to tightening threshold voltage and subthreshold swing distribution since Poly-Si grain size regrows for better grain size distribution with local grains optimization. As an enabler for next-generation technologies, laser thermal annealing will be highly applied in 3D NAND Flash for better device performance with stacking more layers, and opening new opportunities of novel 3D architectures in the semiconductor industry.
TL;DR: In this article , the diffusion characteristics of ion-implanted phosphorus before/after MWA were analyzed. But the dose listed in the figure caption is incorrect. And they did not mention the concentration in the text of the letter.
Abstract: In The above letter [1] , the SIMS profiles in Fig. 1 are for diffusion characteristics of ion-implanted phosphorus before/after MWA. We did not mention the concentration in the text of the letter. However, the dose listed in the figure caption is incorrect. The conclusions of this letter will not be impacted by the revision.
07 Mar 2023
TL;DR: In this article , the authors reported highly effective silicon ion implant activation in GaN via Symmetrical Multicycle Rapid Thermal Annealing (SMRTA) at peak temperatures of 1450 to 1530 °C, producing a mobility of up to 137 cm2/Vs at 300K with a 57% activation efficiency for a 300 nm thick 1 × 1019 cm−3 box implant profile.
Abstract: Selective area doping via ion implantation is crucial to the implementation of most modern devices and the provision of reasonable device design latitude for optimization. Herein, we report highly effective silicon ion implant activation in GaN via Symmetrical Multicycle Rapid Thermal Annealing (SMRTA) at peak temperatures of 1450 to 1530 °C, producing a mobility of up to 137 cm2/Vs at 300K with a 57% activation efficiency for a 300 nm thick 1 × 1019 cm−3 box implant profile. Doping activation efficiency and mobility improved alongside peak annealing temperature, while the deleterious degradation of the as-grown material electrical properties was only evident at the highest temperatures. This demonstrates efficient dopant activation while simultaneously maintaining low levels of unintentional doping and thus a high blocking voltage potential of the drift layers for high-voltage, high-power devices. Furthermore, efficient activation with high mobility has been achieved with GaN on sapphire, which is known for having relatively high defect densities but also for offering significant commercial potential due to the availability of cheap, large-area, and robust substrates for devices.
TL;DR: In this paper , the authors investigated the optimization of the activation-annealing process through the modulation of its process temperature and showed that fine temperature optimization is a necessary procedure for ensuring highly performant and reliable low-temperature polycrystalline silicon (LTPS) TFTs on flexible substrates.
TL;DR: In this paper , a phosphorus drive-in into a high resistivity (100) Si substrate is achieved by an advanced doping technology, providing precise control over the amount of electrically active impurity dopants that are introduced into the semiconductor.