International Business Machines Corporation

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Silke Hildegard Christiansen

Alfred Grill

Patricia May Mooney

Jack Oon Chu

Guy M Cohen

Jens Christiansen

Joachim Jacoby

Kai Christiansen

A method to obtain thin (less than 300 nm) strain-relaxed SiGebuffer layers on Si or silicon-on-insulator (SOI) substrates. These buffer layers have a homogeneous distribution of misfit dislocations that relieve the strain, remarkably smooth surfaces, and a low threading dislocation (TD) density, i.e. less than 10cm. The approach begins with the growth of a pseudomorphic or nearly pseudomorphic SiGelayer, i.e., a layer that is free of misfit dislocations, which is then implanted with He or other light elements and subsequently annealed to achieve the substantial strain relaxation. The very effective strain relaxation mechanism operating with this method is dislocation nucleation at He-induced platelets (not bubbles) that lie below the Si/SiGeinterface, parallel to the Si(001) surface.

Relaxed SiGe layers on Si or silicon-on-insulator substrates by ion implantation and thermal annealing

A method of fabricating relaxed SiGe buffer layers with low threading dislocation densities on silicon-on-insulator (SOI) substrates is provided. The relaxed SiGe buffer layers are fabricated by the epitaxial deposition of a defect-free Stranski-Krastanov Ge or SiGe islands on a surface of the SOI substrate; the capping and planarizing of the islands with a Si or Si-rich SiGe layer, and the annealing of the structure at elevated temperatures until intermixing and thereby formation of a relaxed SiGe layer on the insulating layer (i.e., buried oxide layer) of the initial SOI wafer is achieved. The present invention is also directed to semiconductor structures, devices and integrated circuits which include at least the relaxed SiGe buffer layer mentioned above.

Method for fabrication of relaxed SiGe buffer layers on silicon-on-insulators and structures containing the same

The invention describes a gas laser comprising a container ( ) intended to receive a gas or a gas mixture as laser-active medium, the container ( ) having an axis ( ) along which the gas laser emits its laser radiation, and comprising further means for generating a plasma in the container ( ) and means for generating a magnetic field in the container ( ). It is provided according to the invention that a group of at least two pairs of magnet poles is arranged, with the poles ( ) extending at a distance from, and along the axis ( ) and being arranged around the axis ( ) with alternating polarity so that the magnetic field emanating from them exhibits an intensity sink in the region of the axis ( ), and that the means for generating the plasma include a source for an electromagnetic alternating field, which is associated to the container ( ).

Gas laser

A method for fabricating a strained Si layer on insulator, a structure of the strained Si layer on insulator, and electronic systems comprising such layers are disclosed. The method comprises the steps of forming epitaxially a relaxed SiGe layer on top of a Si layer on insulator; transforming the crystalline Si layer and the lower portion of the crystalline relaxed SiGe layer into an amorphous material state by ion implantation; and re-crystallizing the amorphous material from the crystalline top portion of the SiGe layer. The larger lattice constant of the SiGe seed layer forces a tensile strain in the Si layer.

Strained silicon-on-insulator (SSOI) and method to form the same

A method to obtain thin (<300 nm) strain-relaxed Si Ge buffer layers on Si or silicon-on-insulator (SOI) substrates. These buffer layers have a homogeneous distribution of misfit dislocations that relieve the strain, remarkably smooth surfaces, and a low threading dislocation (TD) density, i.e. <10 cm . The approach begins with the growth of a pseudomorphic Si Ge layer, i.e., a layer that is free of misfit dislocations, which is then implanted with He or other light elements and subsequently annealed to achieve the substantial strain relaxation. The very effective strain relaxation mechanism operating with this method is dislocation nucleation at He-induced platelets (not bubbles) that lie below the Si/Si Ge interface, parallel to the Si(001) surface.

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Halle, Germany

Silke Hildegard Christiansen