TY - JOUR
T1 - Extended Compositional Range for the Synthesis of SWIR and LWIR Ge1-ySnyAlloys and Device Structures via CVD of SnH4and Ge3H8
AU - Mircovich, Matthew A.
AU - Xu, Chi
AU - Ringwala, Dhruve A.
AU - Poweleit, Christian D.
AU - Menéndez, José
AU - Kouvetakis, John
N1 - Funding Information:
This work was partially funded by the AFOSR under grant FA9550-17-1-0314. Additional support was provided by a DARPA STTR through Freedom Photonics LLC.
Funding Information:
This work was partially funded by the AFOSR under grant FA9550-17-1-0314. Additional support was provided by a DARPA STTR through Freedom Photonics LLC.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/24
Y1 - 2021/8/24
N2 - A chemical vapor deposition (CVD) strategy is presented for the synthesis of Ge1-ySny alloys on Si wafers with band gaps in the short-wave infrared (SWIR) range of 1.8-2.6 μm, as well as in the long-wave infrared (LWIR) at 12 μm and beyond. This broad compositional versatility is achieved by CVD reactions of Ge3H8 and SnH4 as Ge and Sn precursors, respectively. The use of conventional SnH4 instead of the previously used SnD4 is found to be critical in synthesizing alloys with Sn contents between 30 and 36%, suggesting that at very low temperatures required to grow these supersaturated alloys, the incorporation of Sn is reaction-rate-dependent. The SnD4 precursor was historically preferred to SnH4 due to its longer lifetime at room temperature. However, the difference is found not to be significant from a practical perspective, and the fact that SnH4 can be synthesized from cheap and readily available starting materials represents a significant cost reduction and portends feasibility for commercial applications. The subtle differences between SnD4 and SnH4 that may explain why alloys with Sn incorporation higher than 30% can only be achieved with the latter are discussed in detail. Optical experiments indicate that such concentrations may be sufficient to cover much of the LWIR range. Device structures containing SWIR Ge1-ySny alloys were grown with the SnH4 precursor to demonstrate its suitability as a viable Sn source. The fabricated heterostructure pin diodes display excellent structural properties and a clear rectifying behavior, providing evidence that SnH4 is a practical and versatile CVD source of Sn at all concentrations of practical interest.
AB - A chemical vapor deposition (CVD) strategy is presented for the synthesis of Ge1-ySny alloys on Si wafers with band gaps in the short-wave infrared (SWIR) range of 1.8-2.6 μm, as well as in the long-wave infrared (LWIR) at 12 μm and beyond. This broad compositional versatility is achieved by CVD reactions of Ge3H8 and SnH4 as Ge and Sn precursors, respectively. The use of conventional SnH4 instead of the previously used SnD4 is found to be critical in synthesizing alloys with Sn contents between 30 and 36%, suggesting that at very low temperatures required to grow these supersaturated alloys, the incorporation of Sn is reaction-rate-dependent. The SnD4 precursor was historically preferred to SnH4 due to its longer lifetime at room temperature. However, the difference is found not to be significant from a practical perspective, and the fact that SnH4 can be synthesized from cheap and readily available starting materials represents a significant cost reduction and portends feasibility for commercial applications. The subtle differences between SnD4 and SnH4 that may explain why alloys with Sn incorporation higher than 30% can only be achieved with the latter are discussed in detail. Optical experiments indicate that such concentrations may be sufficient to cover much of the LWIR range. Device structures containing SWIR Ge1-ySny alloys were grown with the SnH4 precursor to demonstrate its suitability as a viable Sn source. The fabricated heterostructure pin diodes display excellent structural properties and a clear rectifying behavior, providing evidence that SnH4 is a practical and versatile CVD source of Sn at all concentrations of practical interest.
KW - absorption
KW - chemical vapor deposition
KW - long-wave infrared range
KW - stannane
KW - tin-germanium alloys
KW - trigermane
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U2 - 10.1021/acsaelm.1c00424
DO - 10.1021/acsaelm.1c00424
M3 - Article
AN - SCOPUS:85114025292
SN - 2637-6113
VL - 3
SP - 3451
EP - 3460
JO - ACS Applied Electronic Materials
JF - ACS Applied Electronic Materials
IS - 8
ER -