Two-dimensional semiconductor materials, represented by transition metal dichalcogenides (TMDCs), have the characteristics of extreme thickness, high mobility, and back-end heterogeneous integration. They are expected to continue Moore's law and realize integrated circuits with three-dimensional architecture. and industry attention. After nearly a decade of development, two-dimensional electronics has made great progress, but there are still challenges in the preparation of large-area single crystals, key device processes, and compatibility with mainstream semiconductor technologies.
Rannsóknarhópur prófessors Xinran Wang frá rafeindavísinda- og verkfræðideild Nanjing háskólans einbeitti sér að ofangreindum vandamálum og rannsakaði byltingarkennd í lykiltækni tvívíddar hálfleiðara einskristalframleiðslu og heteró- samþættingu, sem gaf nýjar hugmyndir um þróun samþættra hringrása á -Moore tímum eftir. Viðeigandi rannsóknarniðurstöður hafa verið birtar í Nature Nanotechnology nýlega.
Building "atomic terraces" down-to-earth, breaking through two-dimensional semiconductor single crystal epitaxy
Hálfleiðara einkristal efni eru hornsteinn örra rafeindaiðnaðarins. Í samanburði við almennar 12-tommu einkristallaðar sílikonplötur, er undirbúningur tveggja-hálfleiðara enn á litlu-stigi og fjölkristölluðu stigi. Þróun á stórum-svæða, hágæða einkristalluðum þunnum filmum er fyrsta skrefið í átt að tvívíddar samþættum hringrásum. . Hins vegar, meðan á vexti tvívíddar efna stendur, myndast milljónir smásjárflaga af handahófi, og það er aðeins hægt að fá einkristalt efni með því að stjórna öllum flögum til að viðhalda nákvæmlega samræmdri uppröðunarstefnu.
Sapphire is a widely used substrate in the semiconductor industry and has outstanding advantages in mass production, low cost and process compatibility. The collaborating team proposed a scheme to artificially construct atomic-scale "terraces" by changing the direction of the atomic steps on the sapphire surface. The directional growth of TMDCs was achieved by the directional induced nucleation mechanism of "atomic terraces".
Based on this principle, the team achieved the epitaxial growth of a 2-inch MoS2 single crystal film for the first time in the world. Thanks to the improvement of material quality, the mobility of field effect transistors based on MoS2 single crystal is as high as 102.6 cm2/Vs, and the current density reaches 450 μA/μm, which is one of the highest comprehensive performances reported internationally. At the same time, the technology has good universality and is suitable for the preparation of single crystals of other materials such as MoSe2. This work has laid a material foundation for the application of TMDC in the field of integrated circuits.
Þegar litið er upp á stjörnurnar, færa tvívíddar hálfleiðarar-ljós til framtíðarskjátækni
Byltingin á stóru-flatarmáli eins-kristallaefni gerir kleift að beita tvívíddum hálfleiðurum. Í seinni verkinu, sem byggist á margra ára uppsöfnun þriðju-kynslóðar hálfleiðararannsókna, ásamt nýjustu tvívíddar hálfleiðara einkristallausninni, lagði samstarfshópur Rafeindaskólans fram einlita samþætta ofurleiðara lausn. -há-örupplausn Micro LED skjár byggður á MoS2 þunnfilmu smára drifrás. Tæknilegar lausnir.
Micro LED vísar til tækni sem notar míkron-skala LED sem ljós-geislandi pixlaeiningar og setur þær saman með drifeiningum til að mynda skjáfylki með mikilli-þéttleika. Í samanburði við núverandi almenna skjátækni eins og LCD og OLED, hefur Micro LED yfirburði-kynslóða hvað varðar birtustig, upplausn, orkunotkun, endingartíma, viðbragðshraða og hitastöðugleika, og er alþjóðlega viðurkennd næsti{ {4}}kynslóð skjátækni.
Hins vegar stendur iðnvæðing Micro LED enn frammi fyrir mörgum áskorunum. Í fyrsta lagi er erfitt að passa við aksturskröfur skjáeininga með miklum-þéttleika í litlum stærðum. Í öðru lagi er erfitt að mæta þróunarþörfum skjáa með mikilli-upplausn með tilliti til kostnaðar og afraksturs með fjöldaflutningstækni sem er vinsæl í greininni. Sérstaklega fyrir forrit með ofur-hári-upplausn eins og AR/VR, þarf ekki aðeins að upplausnin fari yfir 3000PPI, heldur þurfa skjápunktarnir að hafa hraðari svörunartíðni.
The cooperative team aimed at the field of high-resolution micro-display, and proposed a technical solution for the 3D monolithic integration of MoS2 thin-film transistor driver circuit and GaN-based Micro LED display chip. The team developed a non-"massive transfer" low-temperature monolithic heterogeneous integration technology, using a nearly non-destructive large-size two-dimensional semiconductor TFT manufacturing process, to achieve a high-brightness, high-resolution microdisplay of 1270 PPI, which can meet the needs of future microdisplays. Display, vehicle display, visible light communication and other cross-field applications.
Among them, compared with the traditional two-dimensional semiconductor device process, the new process developed by the team improves the performance of thin film transistors by more than 200 percent , reduces the difference by 67 percent , and the maximum driving current exceeds 200 μA/μm, which is better than IGZO, LTPS and other commercial materials. It shows the huge application potential of two-dimensional semiconductor materials in the display driving industry. This work is the first in the world to integrate two emerging technologies of high-performance two-dimensional semiconductor TFT and Micro LED, which provides a new technical route for the future development of Micro LED display technology.
The above works are respectively named "Epitaxial growth of wafer-scale molybdenum disulfide semiconductor single crystals on sapphire" (corresponding authors are Prof. Wang Xinran and Prof. Wang Jinlan of Southeast University) and "Three dimensional monolithic Micro LED display driven by atomically-thin transistor matrix" (corresponding authors). It was published online in Nature Nanotechnology recently.
This series of work has been supported by projects such as Jiangsu Province's Frontier Leading Technology Basic Research Project, the National Natural Science Foundation of China, and the National Key RD Program. Changchun Institute of Optics and Mechanics, Chinese Academy of Sciences, Tianma Microelectronics Co., Ltd., Nanjing Huanxuan Semiconductor Co., Ltd., etc.
