3. Epitaxial thin film ulu
Hāʻawi ka substrate i kahi papa kākoʻo kino a i ʻole conductive layer no nā mea mana Ga2O3. ʻO ka papa koʻikoʻi e hiki mai ana, ʻo ia ka papa kahawai a i ʻole ka papa epitaxial i hoʻohana ʻia no ka pale ʻana i ka volta a me ka lawe lawe. I mea e hoʻonui ai i ka voltage breakdown a hōʻemi i ke kūpaʻa conduction, ʻo ka mānoanoa hiki ke hoʻopaʻa ʻia a me ka neʻe ʻana o ka doping, a me ka maikaʻi o nā mea waiwai, kekahi mau koi. Hoʻokomo pinepine ʻia nā papa epitaxial Ga2O3 kiʻekiʻe me ka hoʻohana ʻana i ka molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD), halide vapor deposition (HVPE), pulsed laser deposition (PLD), a me nā ʻenehana hoʻoheheʻe CVD.
Papa 2 Kekahi mau 'ike loea epitaxial
3.1 ʻano MBE
Kaulana ʻia ka ʻenehana MBE no kona hiki ke hoʻoulu i nā kiʻiʻoniʻoni β-Ga2O3 kiʻekiʻe, kīnā ʻole me ka doping n-type hiki ke hoʻomalu ʻia ma muli o kona ʻano ʻūhā kiʻekiʻe kiʻekiʻe a me ka maʻemaʻe kiʻekiʻe. ʻO ka hopena, ua lilo ia i hoʻokahi o nā ʻenehana deposition kiʻiʻoniʻoni lahilahi β-Ga2O3 i aʻo nui ʻia a hiki ke kūʻai ʻia. Eia hou, ua hoʻomākaukau maikaʻi ke ʻano MBE i kahi kiʻekiʻe kiʻekiʻe, haʻahaʻa-doped heterostructure β-(AlXGa1-X)2O3/Ga2O3 kiʻi ʻoniʻoni lahilahi. Hiki i ka MBE ke nānā i ke ʻano o ka ʻili a me ka morphology i ka manawa maoli me ka pololei o ka papa atomika ma o ka hoʻohana ʻana i ka hoʻohālikelike electron diffraction kiʻekiʻe (RHEED). Eia nō naʻe, ke kū nei nā kiʻiʻoniʻoni β-Ga2O3 me ka hoʻohana ʻana i ka ʻenehana MBE i nā pilikia he nui, e like me ka ulu haʻahaʻa a me ka nui o ke kiʻiʻoniʻoni liʻiliʻi. Ua ʻike ʻia ka haʻawina ʻo ka nui o ka ulu ʻana ma ke ʻano o (010)>(001)>(−201)>(100). Ma lalo o nā kūlana Ga-waiwai liʻiliʻi o 650 a 750 ° C, hōʻike ʻo β-Ga2O3 (010) i ka ulu maikaʻi loa me ka ʻili maʻemaʻe a me ka ulu kiʻekiʻe. Ke hoʻohana nei i kēia ʻano hana, ua hoʻokō maikaʻi ʻia ka epitaxy β-Ga2O3 me kahi ʻākeke RMS o 0.1 nm. β-Ga2O3 I loko o kahi kaiapuni Ga-waiwai, hōʻike ʻia nā kiʻiʻoniʻoni MBE i ulu i nā mahana like ʻole ma ke kiʻi. Ua hoʻopuka maikaʻi ʻo Novel Crystal Technology Inc. i ka epitaxially 10 × 15mm2 β-Ga2O3MBE wafers. Hāʻawi lākou i ke kūlana kiʻekiʻe (010) β-Ga2O3 hoʻokahi substrates kristal me ka mānoanoa o 500 μm a me XRD FWHM ma lalo o 150 arc kekona. ʻO ka substrate he Sn doped a Fe doped. ʻO ka Sn-doped conductive substrate he doping concentration o 1E18 a 9E18cm−3, aʻo ka hao-doped semi-insulating substrate he resistivity kiʻekiʻe ma mua o 10E10 Ω cm.
3.2 ʻano MOCVD
Hoʻohana ʻo MOCVD i nā mea hoʻohui metala ma ke ʻano he kumu mua e ulu ai i nā kiʻiʻoniʻoni lahilahi, a laila e loaʻa ai ka hana pāʻoihana nui. Ke ulu nei ʻo Ga2O3 me ka hoʻohana ʻana i ke ʻano MOCVD, trimethylgallium (TMGa), triethylgallium (TEGa) a me Ga (dipentyl glycol formate) e hoʻohana mau ʻia e like me ke kumu Ga, ʻoiai ʻo H2O, O2 a i ʻole N2O ke kumu o ka oxygen. Pono ka ulu ʻana me kēia ʻano hana i nā mahana kiʻekiʻe (> 800°C). Hiki i kēia ʻenehana ke hoʻokō i ka manaʻo haʻahaʻa haʻahaʻa a me ke kiʻekiʻe a me ka haʻahaʻa haʻahaʻa electron mobility, no laila he mea koʻikoʻi nui ia i ka hoʻokō ʻana i nā mana mana β-Ga2O3 kiʻekiʻe. Ke hoʻohālikelike ʻia me ke ʻano ulu MBE, loaʻa iā MOCVD ka pōmaikaʻi o ka loaʻa ʻana o nā kiʻi kiʻekiʻe kiʻekiʻe o nā kiʻiʻoniʻoni β-Ga2O3 ma muli o nā hiʻohiʻona o ka ulu ʻana o ka wela kiʻekiʻe a me nā hopena kemika.
Kiʻi 7 β-Ga2O3 (010) kiʻi AFM
Kiʻi 8 β-Ga2O3 ʻO ka pilina ma waenaμa me ka pale pale i ana ʻia e Hall a me ka mahana
3.3 Hana HVPE
ʻO ka HVPE kahi ʻenehana epitaxial makua a ua hoʻohana nui ʻia i ka ulu epitaxial o III-V compound semiconductors. ʻIke ʻia ʻo HVPE no kāna kumu kūʻai haʻahaʻa haʻahaʻa, ulu wikiwiki, a me ka mānoanoa kiʻiʻoniʻoni kiʻekiʻe. Pono e hoʻomaopopo ʻia ʻo ka HVPEβ-Ga2O3 ke hōʻike pinepine nei i ka morphology o ka ʻili a me ke kiʻekiʻe kiʻekiʻe o nā kīnā ʻili a me nā lua. No laila, koi ʻia nā kaʻina polishing kemika a me ka mechanical ma mua o ka hana ʻana i ka hāmeʻa. Hoʻohana maʻamau ka ʻenehana HVPE no ka β-Ga2O3 epitaxy i ke kinoea GaCl a me O2 ma ke ʻano he mea mua e hāpai i ka hopena wela kiʻekiʻe o ka (001) β-Ga2O3 matrix. Hōʻike ka Figure 9 i ke kūlana o ka ʻili a me ka ulu ʻana o ka kiʻi epitaxial ma ke ʻano he hana o ka mahana. I nā makahiki i hala iho nei, ua loaʻa i ka Novel Crystal Technology Inc. o Iapana ka kūleʻa pāʻoihana koʻikoʻi ma HVPE homoepitaxial β-Ga2O3, me ka mānoanoa papa epitaxial o 5 a 10 μm a me ka nui wafer o 2 a me 4 iniha. Eia kekahi, 20 μm mānoanoa HVPE β-Ga2O3 homoepitaxial wafers i hana ʻia e China Electronics Technology Group Corporation i komo pū i ke kahua kūʻai.
Helu 9 HVPE ala β-Ga2O3
3.4 PLD ala
Hoʻohana nui ʻia ka ʻenehana PLD e waiho i nā kiʻiʻoniʻoni oxide paʻakikī a me nā heterostructure. I ka wā o ka ulu ʻana o ka PLD, hoʻohui ʻia ka ikehu photon i ka mea i hoʻopaʻa ʻia ma o ke kaʻina hana electron. Hoʻohālikelike ʻia me MBE, hoʻokumu ʻia nā ʻāpana kumu PLD e ka hoʻoheheʻe laser me ka ikehu kiʻekiʻe loa (> 100 eV) a waiho ʻia ma kahi substrate wela. Eia nō naʻe, i ka wā o ke kaʻina hana ablation, e hoʻopili pololei kekahi mau mea ikaika kiʻekiʻe i ka ʻili o ke kino, e hana ana i nā hemahema kiko a pēlā e hōʻemi ai i ka maikaʻi o ke kiʻiʻoniʻoni. E like me ke ʻano MBE, hiki ke hoʻohana ʻia ʻo RHEED e nānā i ke ʻano o ka ʻili a me ka morphology o ka mea i ka manawa maoli i ka wā o ka PLD β-Ga2O3 deposition process, e ʻae i nā mea noiʻi e loaʻa pololei ka ʻike ulu. Manaʻo ʻia ke ʻano PLD e ulu i nā kiʻiʻoniʻoni β-Ga2O3 conductive kiʻekiʻe, e hoʻolilo iā ia i hoʻonā hoʻopili ohmic i hoʻopaʻa ʻia i nā mana mana Ga2O3.
Kiʻi 10 AFM kiʻi o Si doped Ga2O3
3.5 ʻano MIST-CVD
ʻO MIST-CVD kahi ʻenehana ulu kiʻiʻoniʻoni maʻalahi a maʻalahi. Hoʻopili kēia ʻano CVD i ka pane ʻana o ka pīpī ʻana i kahi precursor atomized ma luna o kahi substrate e hoʻokō ai i ka waiho ʻana o ke kiʻiʻoniʻoni lahilahi. Eia nō naʻe, i kēia manawa, ʻo Ga2O3 i ulu me ka noe CVD ʻaʻole i loaʻa nā waiwai uila maikaʻi, e waiho ana i kahi lumi nui no ka hoʻomaikaʻi ʻana a me ka hoʻomaikaʻi ʻana i ka wā e hiki mai ana.
Ka manawa hoʻouna: Mei-30-2024