Large single-crystal Ge-on-insulator by thermally-assisted (~400 °C) Si-seeded-pulse-laser annealing. (1st November 2017)

• Record Type: Journal Article
• Authors: Sadoh, T.; Kurosawa, M.; Heya, A.; Matsuo, N.; Miyao, M.
• Is Part Of: Materials science in semiconductor processing. Volume 70(2017)
• Page Start: 8
• Page End: 11
• Publication Date: 2017-11-01
• Subjects: Ge -- Rapid-melting growth -- Laser annealing -- 3-dimensional LSI; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2016.10.033
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Low temperature (≤400 °C) formation of orientation-controlled large (≥10 µm) Ge-on-insulator (GOI) structures is desired to fabricate 3-dimensional large-scale integrated circuits (LSIs), where Ge-based functional devices are stacked on Si-LSIs. For this purpose, Si-seeded pulse-laser annealing (PLA) combined with low-temperature substrate heating (≤400 °C) has been developed. Here, a-Ge stripes on Si substrates partially covered with insulating films are subjected to PLA, where single edges of the a-Ge stripes directly contact Si-seeding substrates through opening windows of insulating films. PLA at room temperature generates lateral growth of Ge layers from Si-seeding substrates. However, the growth length is short (~1 µm), which is attributed to very short melting time. To increase the melting time, low-temperature (≤400 °C) substrate heating during PLA is examined. As a result, very large (~20 µm) orientation-controlled GOI is obtained by combining substrate heating (400 °C) with PLA. Detailed electron microscopy analysis reveals very high crystallinity of the grown layers. Consequently, high-quality rapid-melting growth of Ge becomes possible at a low processing temperature of ~400 °C. This thermally-assisted (~400 °C) Si-seeded PLA will facilitate realization of 3-dimensional LSIs.