Nheyo dzeUnyanzvi uye Maitiro e LED Epitaxial Wafers

Kubva pakushanda kwema LED, zviri pachena kuti epitaxial wafer material ndiyo chinhu chikuru che LED. Kutaura zvazviri, ma optoelectronic parameters akakosha akadai se wavelength, brightness, uye forward voltage anonyanya kusarudzwa nezvinhu zve epitaxial. Tekinoroji ye epitaxial wafer nemidziyo zvakakosha pakugadzira, ne Metal-Organic Chemical Vapor Deposition (MOCVD) iriyo nzira huru yekukura matinji matete e single-crystal e III-V, II-VI compounds, uye alloys dzawo. Heano mamwe maitiro emangwana mune tekinoroji ye LED epitaxial wafer.

1. Kuvandudzwa kweMaitiro Ekukura Kwematanho Maviri

Parizvino, kugadzirwa kwemabhizimisi kunoshandisa nzira yekukura kwematanho maviri, asi huwandu hwezvinhu zvinogona kuiswa panguva imwe chete hwakaganhurirwa. Kunyange zvazvo masisitimu emawafer matanhatu akura, michina inobata mawafer angangoita makumi maviri ichiri kugadzirwa. Kuwedzera huwandu hwemawafer kunowanzo tungamira pakusakwana kwe epitaxial layers. Kuvandudzwa kweramangwana kuchatarisa kumativi maviri:

• Kugadzira matekinoroji anobvumira kurodha zvinhu zvakawanda mukamuri imwe chete yemhinduro, zvichiita kuti zvive zvakakodzera kugadzirwa kukuru uye kuderedza mari.
• Kufambira mberi kwekushandisa michina yewafer imwe chete inoshanda otomatiki uye inodzokororwa.

2. Tekinoroji yeHydride Vapor Phase Epitaxy (HVPE)

Tekinoroji iyi inoita kuti mafirimu akakora akure nekukurumidza ane huwandu hushoma hwekupararira, izvo zvinogona kushanda senzvimbo dzekuwedzera kwehomoepitaxial uchishandisa dzimwe nzira. Pamusoro pezvo, mafirimu eGaN akaparadzaniswa nesubstrate anogona kuva dzimwe nzira dzeGaN single-crystal chips. Zvisinei, HVPE ine zvipingamupinyi, zvakaita sekuoma kwekutonga ukobvu nemagasi ekugadzirisa anoparadza anotadzisa kuvandudzwa kweGaN material purity.

HVPE-GaN yakasanganiswa neSi-doped

(a) Maumbirwo eSi-doped HPVE-GaN reactor; (b) Mufananidzo we800 μm- ukobvu HPVE-GaN ine Si-doped;

(c) Kupararira kwehuwandu hwemushonga wekutakura wakasununguka pamwe chete nedhayamita yeSi-doped HVPE-GaN

3. Tekinoroji yekukura kweEpitaxial kana kuti Lateral Epitaxial

Nzira iyi inogona kuderedza kuwanda kwe dislocation uye kuvandudza kunaka kwekristaro yeGaN epitaxial layers. Maitiro acho anosanganisira:

• Kuisa GaN layer pane substrate yakakodzera (safire kana SiC).
• Kuisa chifukidzo che polycrystalline SiO₂ pamusoro.
• Kushandisa photolithography uye etching kugadzira mahwindo eGaN uye SiO₂ mask strips.Munguva yekukura kunotevera, GaN inotanga yakamira mumahwindo uye yozokura yakatambanuka pamusoro peSiO₂ strips.

Wafer yeXKH yeGaN-on-Sapphire

4. Tekinoroji yePendeo-Epitaxy

Nzira iyi inoderedza zvakanyanya zvikanganiso zve lattice zvinokonzerwa ne lattice uye kusawirirana kwe thermal pakati pe substrate ne epitaxial layer, zvichiwedzera kuwedzera kunaka kwe crystal ye GaN. Matanho acho anosanganisira:

• Kukura GaN epitaxial layer pane substrate yakakodzera (6H-SiC kana Si) uchishandisa nzira ine matanho maviri.
• Kuita kuchekwa kwechikamu che epitaxial kusvika pasi pevhu, kugadzira pillar inochinjana (GaN/buffer/substrate) uye trench structures.
• Kuwedzera mamwe maGaN layers, ayo anotambanuka kubva pamadziro emativi eGaN pillars dzepakutanga, akarembera pamusoro pemigero.Sezvo pasina chifukidzo chinoshandiswa, izvi zvinodzivirira kusangana pakati peGaN nezvinhu zvechifukidzo.

Wafer yeXKH yeGaN-on-Silicon

5. Kugadzirwa kwezvinhu zveUV LED Epitaxial zveShort-Wavelength

Izvi zvinoisa hwaro hwakasimba hwema LED machena akagadzirwa ne phosphor anofadzwa ne UV. Ma phosphor akawanda anoshanda zvakanyanya anogona kufadzwa nechiedza che UV, zvichipa kushanda kwakanaka kupfuura system ye YAG:Ce iripo, nokudaro zvichisimudzira kushanda kwe LED chena.

6. Tekinoroji yeChip yeMulti-Quantum Well (MQW)

Muzvivakwa zveMQW, tsvina dzakasiyana dzinoiswa mukati mekukura kwechikamu chinoburitsa chiedza kuti pave nematsime akasiyana-siyana equantum. Kubatanidzwa kwemaphoton anoburitswa kubva mumatsime aya kunogadzira chiedza chichena zvakananga. Nzira iyi inovandudza kushanda zvakanaka kwechiedza, inoderedza mari, uye inoita kuti kurongedza nekudzora macircuit zvive nyore, kunyangwe ichipa matambudziko makuru ehunyanzvi.

7. Kuvandudzwa kweTekinoroji ye "Kudzokorodza Photon"

Muna Ndira 1999, Sumitomo yekuJapan yakagadzira LED chena ichishandisa ZnSe. Tekinoroji iyi inosanganisira kugadzira firimu rakatetepa reCdZnSe paZnSe single-crystal substrate. Kana yaiswa magetsi, firimu iyi inoburitsa chiedza chebhuruu, icho chinosangana neZnSe substrate kuti igadzire chiedza cheyero chinopindirana, zvichikonzera chiedza chena. Saizvozvowo, Photonics Research Center yeBoston University yakaisa AlInGaP semiconductor compound paGaN-LED yebhuruu kuti igadzire chiedza chena.

8. Kuyerera kweEpitaxial Wafer ye LED

① Kugadzirwa kweWafer yeEpitaxial:
Substrate → Dhizaini yechivakwa → Kukura kwechikamu cheBuffer → Kukura kwechikamu cheGaN cherudzi rweN → Kukura kwechikamu cheMQW chinoburitsa chiedza → Kukura kwechikamu cheGaN cherudzi rweP → Kunyungudutsa → Kuyedza (photoluminescence, X-ray) → Epitaxial wafer

② Kugadzira Chip:
Epitaxial wafer → Kugadzirwa uye kugadzirwa kwemasiki → Photolithography → Ion etching → N-type electrode (deposition, annealing, etching) → P-type electrode (deposition, annealing, etching) → Dicing → Kuongorora uye kuyera Chip.

Wafer yeZMSH yeGaN-on-SiC