Soitec

S.o.i.tec Silicon on Insulator Technologies

Alexandre Vaufredaz

Sébastien Kerdiles

Carine Duret

Frédéric Metral

Sebastien Molinari

The invention relates to a process for fabricating a multilayer structure that includes bonding a first wafer onto a second wafer, where the first wafer may have a chamfered edge and the bonding interface has an adhesion energy of less than or equal to 1 J/m, and thinning the first wafer so as to form a transferred layer, where before thinning the first wafer, a step of trimming the edge of the first wafer is carried out using a grinding wheel having a working surface which comprises grit particles with an average size of greater than or equal to 800 mesh or less than or equal to 18 microns, and wherein the trimming step is carried out by lowering the grinding wheel at a rate of descent of greater than or equal to 5 microns per second, such that the descent of the grinding wheel into the first wafer continues to a distance from the bonding interface that is less than or equal to 30 &#x3bc;m.

Process for fabricating a multilayer structure with trimming using thermo-mechanical effects

A process for fabricating a heterostructure by bonding a first wafer to a second wafer, with the first wafer having a thermal expansion coefficient that is lower than the thermal expansion coefficient of the second wafer, and conducting at least one bond-strengthening annealing step. After the bonding step and before the bond-strengthening annealing step, at least one trimming step is conducted in which the first wafer is at least partially trimmed.

Process for fabricating a heterostructure with minimized stress

The invention relates to a process for fabricating a multilayer structure comprising: bonding a first wafer onto a second wafer, at least the first wafer having a chamfered edge; and thinning the first wafer so as to form in a transferred layer, the thinning comprising a grinding step and a chemical etching step. After the grinding step and before the chemical etching step, a trimming step of the edge of the first wafer is carried out using a grinding wheel, the working surface of which comprises grit particles having an average size of less than or equal to 800-mesh or greater than or equal to 18 microns, the trimming step being carried out to a defined depth in the first wafer so as to leave a thickness of the first wafer of less than or equal to 35 &#x3bc;m in the trimmed region.

Process for fabricating a multilayer structure with post-grinding trimming

The invention relates to a process for bonding by molecular adhesion of two substrates to one another during which the surfaces of the substrates are placed in close contact and bonding occurs by propagation of a bonding front between the substrates. The invention includes, prior to bonding, a step of modifying the surface state of one or both of the surfaces of the substrates so as to regulate the propagation speed of the bonding front. The surface can be modified by locally or uniformly heating or roughening the surface(s) of the substrate(s).

Process for bonding by molecular adhesion

The invention relates to equipment for carrying out a process for bonding by molecular adhesion of two substrates to one another during which the surfaces of the substrates are placed in close contact and bonding occurs by propagation of a bonding front between the substrates. The invention includes, prior to bonding, a step of modifying the surface state of one or both of the surfaces of the substrates so as to regulate the propagation speed of the bonding front. The surface can be modified by locally or uniformly heating or roughening the surface(s) of the substrate(s).

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Voiron, France

Alexandre Vaufredaz