(Invited) Mechanics of Wafer Bonding and Layer Transfer Processes

ABSTRACTEngineered substrates are expected to play a dominant role in the field of modern nano-electronic and optoelectronic technologies. For example, engineered substrates like SOI (Silicon On Insulator) make possible efficient optimization of transistors' current drive while minimizing the leakage and reducing parasitic elements, thus enhancing the overall IC performance in terms of speed or power consumption. Other generations of engineered substrates like strained SOI (sSOI) provide solutions to traditional scaling for 32 nm node and beyond [1] technologies.The Smart Cutä technology, introduced in the mid 1990's by M. Bruel [2] is a revolutionnary and powerful thin film technology for bringing to industrial maturity engineered substrate solutions. It is a combination of wafer bonding and layer transfer via the use of ion implantation. It allows multiple high quality transfers of thin layers, from a single crystal donor wafer onto another substrate of a different nature, allowing the integration of dissimilar materials. As a consequence, it opens the path to the formation of III-V based engineered substrates by integrating, for example, materials like GaAs [3], InP [4], SiC [5], GaN [6], Germanium [7] ,and Si [8 ]on a silicon, poly SiC, sapphire, ceramic, or metal substrates?In this paper, we will review the current wafer bonding and layer transfer technologies with a special emphasis on the Smart Cut technology applied to compound semiconductors. Beyond SOI, the innovation provided by substrate engineering will be illustrated by the case of Silicon and SiC engineered substrate serving as a platform for GaN and related alloys processing [9,10,11,12] as well as the case of Germanium/Si platform for the growth of GaAs/InP materials, opening the path to Si CMOS and III-V microelectronics/ optoelectronics functions hybrid integration [13, 14]. Recent results obtained in these two focused areas will be presented to emphasize the added functionalities offered by engineered substrates.[1] B. Ghyselen et al., ICSI3 proc., 173 5 (2003)[2] M. Bruel et al., Electron. Lett., vol 31, p. 1201 (1995)[3] E. Jalaguier et al., Electron. Lett., 34(4), 408 (1998)[4] E. Jalaguier et al. Proc. llth Intern. Conf. on InP and Related Materials, Davos, Switzerland, (1999)[5] L. Di Cioccio et al., Mat. Sci. and Eng. B Vol. 46, p. 349 (1997)[6] A. Tauzin and al., Semiconductor Wafer Bonding VIII, ECS Proc Vol. 2005-02, pp. 119-127[7] F. Letertre, et al. MRS Symp. Proc., 809, B4.4 (2004).[8] B. Faure et al., Semiconductor Wafer Bonding VIII, ECS Proc Vol. 2005-02, pp. 106-118[9] H. Larèche et al., Mat. Sci. For., Vols. 457–460 pp.. 1621 – 1624 (2004)[10] G. Meneghesso et al , IEDM 2007, to be published[11] Y. Dikme et al., Journal of Crystal Growth, v.272 (1-4), pp. 500-505 (2004)[12] J. Dorsaz and al., Proceedings, ICNS6 (2005)[13] S.G. Thomas et al., IEEE EDL Vol. 26, July 2005.[14] K. Chilukuri, Semi. Sci. Technol. 22 (2007) 29-34

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