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.
Prof Xinran Wangi uurimisrühm Nanjingi ülikooli elektroonikateaduste ja tehnika koolist keskendus ülaltoodud probleemidele ja uuris läbimurdeid kahe{0}}üksikkristallide kahemõõtmelise pooljuhtide valmistamise ja hetero- võtmetehnoloogiates. integratsiooni, mis andis uusi ideid integraallülituste arendamiseks Moore'i järgsel ajastul. Asjakohased uurimistulemused on hiljuti avaldatud ajakirjas Nature Nanotechnology.
Building "atomic terraces" down-to-earth, breaking through two-dimensional semiconductor single crystal epitaxy
Pooljuht monokristallmaterjalid on mikroelektroonikatööstuse nurgakivi. Võrreldes tavaliste 12-tolliste monokristalliliste räniplaatidega on kahe-dimensiooniliste pooljuhtide valmistamine veel väikese-mastaabiga ja polükristalliliste plaatidega. Suure-pinnaga kvaliteetsete-monokristalliliste õhukeste kilede väljatöötamine on esimene samm kahe-mõõtmeliste integraallülituste suunas. . Kahe-mõõtmeliste materjalide kasvamise ajal tekib aga juhuslikult miljoneid mikroskoopilisi kiipe ja monoliitset ühekristallmaterjali on võimalik saada ainult siis, kui kõiki kiipe kontrollitakse, et säilitada rangelt ühtne paigutussuund.
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.
Vaadates tähtedele, toovad kahe{0}}mõõtmelised pooljuhid valgust tuleviku kuvatehnoloogiasse
Suure -pindalaga ühe-kristallmaterjalide läbimurre võimaldab kasutada kahe-mõõtmelisi pooljuhte. Teises töös, mis põhines aastaid kestnud kolmanda -põlvkonna pooljuhtide uurimisel ja kombineerituna uusima kahe-dimensioonilise pooljuhtide monokristalllahendusega, pakkus elektroonikakooli koostöömeeskond välja monoliitse integreeritud ultra. -kõrge eraldusvõimega-mikro-LED-ekraan, mis põhineb MoS2 õhukese kilega transistori draiveri ahelal. Tehnilised lahendused.
Mikro-LED viitab tehnoloogiale, mis kasutab mikron-skaala LED-e valgust-kiirgavate piksliüksustena ja ühendab need juhtmoodulitega, et moodustada suure-tihedusega kuvamassiivi. Võrreldes praeguste tavaliste ekraanitehnoloogiatega, nagu LCD ja OLED, on Micro LED-il üle-põlvkondadevahelised eelised heleduse, eraldusvõime, energiatarbimise, tööea, reageerimiskiiruse ja termilise stabiilsuse osas ning see on rahvusvaheliselt tunnustatud järgmine{3} {4}}põlvkonna kuvatehnoloogia.
Micro LED-i industrialiseerimine seisab aga endiselt silmitsi paljude väljakutsetega. Esiteks on väikeses suuruses suure{0}}tihedusega kuvaritele raske vastata sõidunõuetele. Teiseks on tööstuses populaarsel massiedastustehnoloogial raske rahuldada kõrge eraldusvõimega kuvarite arendusvajadusi-kulu ja tootlikkuse osas. Eriti üli-kõrge-eraldusvõimega rakenduste (nt AR/VR) puhul ei pea mitte ainult eraldusvõime ületama 3000PPI, vaid ka ekraani pikslitel peab olema kiirem reageerimissagedus.
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.
