Excimer laser assisted spin-on doping of boron into silicon

Lo, Veng Cheong; Wong, Y. W.; Cho, H C; Chen, Y Q; Ho, S M; Chan, Philip Wai Hong; Tong, Kin‐Fai

doi:10.1088/0268-1242/11/9/008

Cited by 3 publications

(2 citation statements)

References 11 publications

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“…The dominant mechanism associated with repeat pulses is the re-melt and re-distribution of the existing dopant atoms within the melt layer, similar to the effect of a traditional thermal 'drive-in' step and resulting in a dopant profile characterized by both lower surface dopant density and greater depth [27,28]. A deeper and flatter profile yields a lower sheet resistance, even for the same total dose, simply because carrier mobility increases with decreasing dopant density [29].…”

Section: Pl Spectra Of Excimer Laser Boron-doped Silicon Substratesmentioning

confidence: 99%

Low-temperature micro-photoluminescence spectroscopy on laser-doped silicon with different surface conditions

et al. 2016

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Low-temperature micro-photoluminescence spectroscopy (μ-PLS) is applied to investigate shallow layers of laser-processed silicon for solar cell applications. Micron-scale measurement (with spatial resolution down to 1 μm) enables investigation of the fundamental impact of laser processing on the electronic properties of silicon as a function of position within the laser-processed region, and in particular at specific positions such as at the boundary/ edge of processed and unprocessed regions. Low-temperature μ-PLS enables qualitative analysis of laser-processed regions by identifying PLS signals corresponding to both laser-induced doping and laser-induced damage. We show that the position of particular luminescence peaks can be attributed to band-gap narrowing corresponding to different levels of subsurface laser doping, which is achieved via multiple 248 nm nanosecond excimer laser pulses with fluences in the range 1.5-4 J/cm 2 and using commercially available boron-rich spin-on-dopant precursor films. We demonstrate that characteristic defect PL spectra can be observed subsequent to laser doping, providing evidence of laser-induced crystal damage. The impact of laser parameters such as fluence and number of repeat pulses on laserinduced damage is also analyzed by observing the relative level of defect PL spectra and absolute luminescence intensity. Luminescence owing to laser-induced damage is observed to be considerably larger at the boundaries of laser-doped regions than at the centers, highlighting the significant role of the edges of laser-doped region on laser doping quality. Furthermore, by comparing the damage signal observed after laser processing of two different substrate surface conditions (chemically-mechanically polished and tetramethylammonium hydroxide etched), we show that wafer preparation can be an important factor impacting the quality of laser-processed silicon and solar cells.

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Section: Pl Spectra Of Excimer Laser Boron-doped Silicon Substratesmentioning

confidence: 99%

Low-temperature micro-photoluminescence spectroscopy on laser-doped silicon with different surface conditions

et al. 2016

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“…In this approach, a solution with a high dopant concentration is spun onto the surface. The film is then solidified by a short bake to create a solid dopant source [28,29]. High efficiencies using different substrates and SODs have been obtained using this method [30][31][32].…”

Section: Introductionmentioning

confidence: 99%