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Ultrathin AlN‐Based HEMTs Grown on Silicon Substrate by NH 3 ‐MBE
Author(s) -
Rennesson Stephanie,
Leroux Mathieu,
Al Khalfioui Mohamed,
Nemoz Maud,
Chenot Sébastien,
Massies Jean,
Largeau Ludovic,
Dogmus Ezgi,
Zegaoui Malek,
Medjdoub Farid,
Semond Fabrice
Publication year - 2018
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201700640
Subject(s) - materials science , silicon , substrate (aquarium) , molecular beam epitaxy , optoelectronics , sapphire , photoluminescence , epitaxy , layer (electronics) , fabrication , hall effect , nanotechnology , electrical resistivity and conductivity , optics , electrical engineering , medicine , laser , oceanography , physics , alternative medicine , pathology , engineering , geology
AlN‐based HEMTs grown on silicon by ammonia‐assisted molecular beam epitaxy (NH 3 ‐MBE) are demonstrated and studied. As shown by photoluminescence, the very thin GaN channel (35–55 nm‐thick) is compressively strained on the 250 nm‐thick relaxed AlN buffer layer grown on silicon substrate. The structure is then completed by an 8 nm‐thick AlN barrier and 2 nm‐thick GaN cap. Despite an ultrathin total epilayer (only ≈300 nm‐thick), a high 2DEG density (≈2.7 × 10 13 cm −2 ) is measured by Hall effect. Room temperature mobility values, as high as 636 cm 2 V −1 s −1 , are measured. They are higher than those reported on similar structures grown on sapphire, SiC and bulk AlN substrates, showing the interest of growing such structures on silicon substrate. Also, low contact resistance values are obtained, as low as 0.18 Ω mm, by using a basic fabrication process.