Foreign Collaborators

Prof. Ishirou Yamaguchi, Optical Engineering Lab., Institute of Physical and Chemical Research (RIKEN), Japan

Prof. K.T.V. Grattan, City University, UK

Dr. Nikos Vainos, IESL, FORTH, Crete, Greece

Dr. P.M. Petersen RISOE National lab, Denmark

Prof. L. Hesselink, Stanford University, USA

№ -0138 Grooved Surface Direct Wafer Bonding Technology for the Design of Semiconductor

Full Title:	Grooved Surface Direct Wafer Bonding Technology for the Design of Semiconductor Devices
Technology Field(s):	INF-ELE: Information and Communications / Microelectronics and Optoelectronics MAT-CER: Materials / Ceramics

Contributors

Ludmila S Kostina

A.F.Ioffe Physico-Technical Institute (Ioffe Inst) 26, Polytechnicheskaya str., St Petersburg, 194021, Russia Phone: 7+812+2479923; 7+812+2473973 Fax: 7+812+2479123; 7+812+2475416 mega@pulse.pti.spb.su

Present Status of Research

Brief Description of Research

A surface-grooved direct wafer bonding (SGDWB) technology for the design of semiconductor devices has been developed for the first time.. Traditional direct bonding involves an attachment of mirror-polished smooth wafer surfaces after special chemical treatment. The main disadvantage of the traditional technique is the formation of a mesoscale damaged region at the bonding interface, which deteriorates the device characteristics. In the new technology, bonding between mirror-polished silicon wafers (one of which has a regular net of grooves) has been realized with almost complete removal of the extended interfacial damaged region. The innovation is based on the fact that, due to dislocation and a peculiar tendency to move towards free surfaces, the wafers can be collected by the grooves. As a result, the at-groove dislocation bundles are formed, while between-the-grooves spaces become almost free from dislocations. In the course of theoretical consideration and experimental study, it has been shown that a mesoscale grooved pattern put into the interfacial bonding region trapped lattice dislocations, impeding their propagation towards the wafer bulk. Continuously bonded void-free surface-grooved p-n-structures with near-interfacial-dislocation densities (not more than 10²-10³ cm^-2) were fabricated and examined. The density-of-state was one order lower and the minority carrier lifetime was 1.5 orders higher than in the same structures with traditionally smooth-smooth interfaces. Grooves are capable of becoming an efficient means for the formation of a smooth void-free boundary.

The suggested technology opens new prospects in the design of semiconductor devices with either electrically conducted or insulating bonding interfaces. For example, in the design of a buried grid gate turn-off thyristor (BGGTO), the application of the developed technique allowed us to combine a high value of n-p-emitter breakdown voltage (up to 300V) with high conductivity of a built-in p-base net of stripes, which yields the control of a large operating area. An easily realizable method of manufacturing a static induction device has also been suggested.

Legal Aspects

The developed technique has already been applied in the design of such complicated devices as a gate turn-off thyristor, a bipolar transistor, a static induction transistor etc. A Patent application for the technology has been approved in Russia.

Special Facilities None in this research.

Scientific Papers

I.V. Grekhov, T.S. Argunova, M.Yu. Gutkin, L.S. Kostina, T.V. Kudryavzeva (Ioffe PTI), “Direct Bonding of Silicon Wafers with Grooved Surfaces: Characterization of Defects and Application to Power Semiconductor Devices”, Material Science Forum, vols. 196-201, pp.1853-1858 (1995).

I.V. Grekhov, T.S. Argunova, M.Yu. Gutkin, L.S. Kostina, T.V. Kudryavzeva (Ioffe PTI), E.D. Kim, S.C. Kim (KERI), “A New Silicon Direct Bonding Technology Employing a Regularly Grooved Surface,” Electronics Letters, vol.31, no.23, pp.2047-2048.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova, I.A. Rol’nik (Ioffe PTI), “A Gate Turn-off Thyristor on the Basis of the SDB Technique,” Proceedings of ISPSD’94, Davos, May 31-June 2, pp. 233-234.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova, I.A. Rol’nik, (Ioffe PTI), “New Design of a Wholly Controlled Bipolar Device,” Phys. Tech. Lett., v.19, no.2, pp.26-29 (1993).

I.V. Grekhov, T.S. Argunova, E.I. Beliakova, L.S. Kostina, T.V. Kudryavzeva (Ioffe PTI), “Direct Bonding of Silicon Wafers with a Regular Relief at the Interface,” Phys. Tech. Lett. vol. 22, no.2, pp.133-135 (1996).

I.V. Grekhov, T.S. Argunova, M.Yu. Gutkin, L.S. Kostina, T.V. Kudryavzeva (Ioffe PTI); E.D. Kim, J.M. Park (KERI), “Dislocations in Silicon Structures Prepared by Direct Bonding of Surfaces with a Relief,” Phys. Solid State, vol.38, no.11, pp.1832-1833 (1996).

E.D. Kim, S.C. Kim, J.M. Park, (KERI); I.V. Grekhov, T.S. Argunova, M.Yu. Gutkin, L.S. Kostina, T.V. Kudryavzeva (Ioffe PTI), “Structural Quality or Directly Bonded Silicon Wafers with Regularly Grooved Interfaces,” J. Electrochem. Soc.,vol.144., no.2, pp. 622-627 (1997).

M.Yu. Gutkin, T.S. Argunova, I.V. Grekhov, L.S. Kostina, I.L. Shul’pina (Ioffe PTI), “X-ray Topographic Study of Directly Bonded Silicon Wafers with Grooved Interfaces,” Collected Abstracts of the 3rd European Symposium on X-ray Topography and High Resolution Diffraction, Palermo, Italy, April 1996, pp.301-305.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova T.V. Kudryavzeva, L.S. Berman (Ioffe PTI); E.D. Kim, S.C. Kim, J.M. Park (KERI), “Power SDB Devices with Regularly Grooved Interfaces,” Collected Abstracts of the 54th Device Research Conference, Santa Barbara, USA, June 24-26, Abstr. no. P174.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova (Ioffe PTI), “Semiconductor Device,” Patent no. 2045111 (Russia), 01.08.1992.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova, “Method of Semiconductor Device Fabrication,” Patent no. 93033880 (Russia), 07.01.1993.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova, T.S. Argunova, T.V. Kudryavzeva (Ioffe PTI), “Method of Fabricating Silicon Structures,” Patent no. 94026881 (Russia), 07.08. 1994.

I.V. Grekhov, L.S. Kostina, E.I. Beliakova, T.V. Kudryavzeva, L.S. Berman, T.S. Argunova (Ioffe PTI); E.D. Kim, S.C. Kim, J.M. Park (KERI), “Recombination Properties of Directly Bonded Silicon Structures with a Regular Relief at the Interface,” Phys. Tech. Lett., vol.22, no.12, pp.956-957 (1996).

Grekhov, L.S. Kostina, E.I. Beliakova, T.V. Kudryavzeva, L.S. Berman, T.S. Argunova (Ioffe PTI); E.D. Kim, S.C. Kim, J.M. Park (KERI), “Interface Properties of a SI-SIO₂-Si Structure Fabricated by a Modified Direct Bonding Technique,” Collected Abstracts of the 5th International Conference on Properties and Applications of Dielectric Materials, Abstr. no. 04P04, Seoul, May 25-30, 1997.