Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate
In recent years, Germanium (Ge) photodiodes have established a widespread utilization in photonic-integrated circuits (PICs). However, the devices commonly exhibit a prominent dark current due to the substantial defects at the Ge/Si heteroepitaxial interface. Herein, we demonstrate normal-incidence,...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2021
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| Online Access: | https://hdl.handle.net/10356/146751 |
| _version_ | 1811679051630247936 |
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| author | Lin, Yiding Son, Bongkwon Lee, Kwang Hong Michel, Jurgen Tan, Chuan Seng |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering Lin, Yiding Son, Bongkwon Lee, Kwang Hong Michel, Jurgen Tan, Chuan Seng |
| author_sort | Lin, Yiding |
| collection | NTU |
| description | In recent years, Germanium (Ge) photodiodes have established a widespread utilization in photonic-integrated circuits (PICs). However, the devices commonly exhibit a prominent dark current due to the substantial defects at the Ge/Si heteroepitaxial interface. Herein, we demonstrate normal-incidence, buffer-less Ge vertical p-i-n photodiodes with remarkably low dark current density (Jdark, 0.78 mA/cm2 at -1 V), on a high-quality 200-mm Ge-on-insulator (GOI) substrate. The high-quality GOI was achieved by the removal of the highly dislocated Ge/Si interfacial region, sequentially via wafer bonding, layer transfer and oxygen (O2) furnace annealing. Compared to un-annealed GOI, the threading dislocation density (TDD) in Ge was reduced by more than two orders of magnitude to 1.2×106 cm-2. Correspondingly, the device Jdark and bulk leakage (Jbulk) were reduced by ~70× and ~145×. On the other hand, the photodiodes present a reasonable responsivity of 0.29 A/W at 1,550 nm and a nearly 100% internal quantum efficiency without external bias. The specific detectivity (D*, 2.17×1010 cm⸱Hz1/2⸱W-1 at 1,550 nm and -0.1 V) is comparable with that of commercial bulk Ge photodiodes. In addition, the low temperature bonding and layer transfer can enable a compact integration at the back-end-of-line for PIC applications. This work paves the way for GOI photodiodes towards advanced high-resolution imaging and sensing applications on PICs at the near infrared and short-wave infrared wavelength. |
| first_indexed | 2024-10-01T03:03:01Z |
| format | Journal Article |
| id | ntu-10356/146751 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:03:01Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1467512021-03-09T06:59:23Z Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate Lin, Yiding Son, Bongkwon Lee, Kwang Hong Michel, Jurgen Tan, Chuan Seng School of Electrical and Electronic Engineering Engineering::Electrical and electronic engineering::Semiconductors Germanium (Ge) Ge-on-insulator In recent years, Germanium (Ge) photodiodes have established a widespread utilization in photonic-integrated circuits (PICs). However, the devices commonly exhibit a prominent dark current due to the substantial defects at the Ge/Si heteroepitaxial interface. Herein, we demonstrate normal-incidence, buffer-less Ge vertical p-i-n photodiodes with remarkably low dark current density (Jdark, 0.78 mA/cm2 at -1 V), on a high-quality 200-mm Ge-on-insulator (GOI) substrate. The high-quality GOI was achieved by the removal of the highly dislocated Ge/Si interfacial region, sequentially via wafer bonding, layer transfer and oxygen (O2) furnace annealing. Compared to un-annealed GOI, the threading dislocation density (TDD) in Ge was reduced by more than two orders of magnitude to 1.2×106 cm-2. Correspondingly, the device Jdark and bulk leakage (Jbulk) were reduced by ~70× and ~145×. On the other hand, the photodiodes present a reasonable responsivity of 0.29 A/W at 1,550 nm and a nearly 100% internal quantum efficiency without external bias. The specific detectivity (D*, 2.17×1010 cm⸱Hz1/2⸱W-1 at 1,550 nm and -0.1 V) is comparable with that of commercial bulk Ge photodiodes. In addition, the low temperature bonding and layer transfer can enable a compact integration at the back-end-of-line for PIC applications. This work paves the way for GOI photodiodes towards advanced high-resolution imaging and sensing applications on PICs at the near infrared and short-wave infrared wavelength. Ministry of Education (MOE) National Research Foundation (NRF) This work was partially supported by the National Research Foundation, Singapore, under its Competitive Research Program (CRP Award NRF-CRP19-2017-01), and partially supported by Ministry of Education AcRF Tier 1 (2019-T1-002-040 RG147/19 (S)) 2021-03-09T06:59:22Z 2021-03-09T06:59:22Z 2021 Journal Article Lin, Y., Son, B., Lee, K. H., Michel, J., & Tan, C. S. (2021). Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate. IEEE Transactions on Electron Devices, 1-8. doi:10.1109/TED.2021.3061362 0018-9383 https://hdl.handle.net/10356/146751 10.1109/TED.2021.3061362 1 8 en IEEE Transactions on Electron Devices © 2021 Institute of Electrical and Electronics Engineers (IEEE). All rights reserved. |
| spellingShingle | Engineering::Electrical and electronic engineering::Semiconductors Germanium (Ge) Ge-on-insulator Lin, Yiding Son, Bongkwon Lee, Kwang Hong Michel, Jurgen Tan, Chuan Seng Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title | Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title_full | Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title_fullStr | Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title_full_unstemmed | Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title_short | Sub-mA/cm² dark current density, buffer-less Germanium (Ge) photodiodes on a 200-mm Ge-on-insulator substrate |
| title_sort | sub ma cm² dark current density buffer less germanium ge photodiodes on a 200 mm ge on insulator substrate |
| topic | Engineering::Electrical and electronic engineering::Semiconductors Germanium (Ge) Ge-on-insulator |
| url | https://hdl.handle.net/10356/146751 |
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