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.
Istraživačka skupina prof. Xinrana Wanga sa Škole za elektroničku znanost i inženjerstvo Sveučilišta Nanjing usredotočila se na gore navedene probleme i istražila otkrića u ključnim tehnologijama dvodimenzionalnih poluvodičkih monokristalnih proizvodnje i hetero- integraciju, što je dalo nove ideje za razvoj integriranih sklopova u post-Mooreovoj eri. Relevantni rezultati istraživanja nedavno su objavljeni u Nature Nanotechnology.
Building "atomic terraces" down-to-earth, breaking through two-dimensional semiconductor single crystal epitaxy
Poluvodički monokristalni materijali su kamen temeljac mikroelektroničke industrije. U usporedbi s uobičajenim 12-inčnim monokristalnim silicijevim pločicama, priprema dvodimenzionalnih poluvodiča-i dalje je u maloj- fazi i polikristalnoj fazi. Razvoj-visokokvalitetnih monokristalnih tankih filmova velike površine-prvi je korak prema dvodimenzionalnim integriranim krugovima-. . Međutim, tijekom rasta dvodimenzionalnih materijala, milijuni mikroskopskih čipova se nasumično generiraju i jedino je moguće dobiti monolitni monokristalni materijal kontroliranjem svih čipova kako bi se održao strogo dosljedan smjer rasporeda.
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.
Gledajući prema zvijezdama, dvodimenzionalni{0}}poluvodiči donose svjetlo budućoj tehnologiji prikaza
Proboj monokristalnih materijala velikih{0}}područja-omogućuje primjenu dvodimenzionalnih-poluvodiča. U drugom radu, na temelju godina akumulacije istraživanja treće{3}}generacije poluvodiča, u kombinaciji s najnovijim dvodimenzionalnim poluvodičkim monokristalnim rješenjem, kooperativni tim Škole za elektroniku predložio je monolitni integrirani ultra Mikro LED zaslon -visoke-razlučivosti baziran na pokretačkom krugu tankoslojnog tranzistora MoS2. Tehnička rješenja.
Mikro LED se odnosi na tehnologiju koja koristi LED diode u mikronskom-razmjeru kao jedinice piksela koje emitiraju svjetlost{1}}i sastavlja ih s pogonskim modulima kako bi se formirao niz prikaza visoke{2}}gustoće. U usporedbi s trenutačnim mainstream tehnologijama zaslona kao što su LCD i OLED, Micro LED ima više-generacijske prednosti u smislu svjetline, razlučivosti, potrošnje energije, vijeka trajanja, brzine odziva i toplinske stabilnosti, te je međunarodno priznati sljedeći{ {4}}generacijska tehnologija prikaza.
Međutim, industrijalizacija Micro LED i dalje se suočava s mnogim izazovima. Prvo, teško je zadovoljiti zahtjeve vožnje za jedinice za prikaz{0} velike gustoće u malim veličinama. Drugo, tehnologija masovnog prijenosa popularna u industriji teško je zadovoljiti razvojne potrebe za zaslone visoke{1}}razlučivosti u smislu cijene i prinosa. Posebno za aplikacije ultra-visoke-razlučivosti kao što je AR/VR, ne samo da je potrebna razlučivost od 3000 PPI, već i pikseli zaslona moraju imati bržu frekvenciju odziva.
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.
