Abstract:
The present invention provides an improved amorphization/templated recrystallization (ATR) method for fabricating low-defect-density hybrid orientation substrates. ATR methods for hybrid orientation substrate fabrication generally start with a Si layer having a first orientation bonded to a second Si layer or substrate having a second orientation. Selected regions of the first Si layer are amorphized and then recrystallized into the orientation of the second Si layer by using the second Si layer as a template. In particular, this invention provides a melt-recrystallization ATR method, for use alone or in combination with non-melt-recrystallization ATR methods, in which selected Si regions bounded by dielectric-filled trenches are induced to undergo an orientation change by the steps of preamorphization, laser-induced melting, and corner-defect-free templated recrystallization from the melt.
Abstract:
Hybrid orientation substrates allow the fabrication of complementary metal oxide semiconductor (CMOS) circuits in which the n-type field effect transistors (nFETs) are disposed in a semiconductor orientation which is optimal for electron mobility and the p-type field effect transistors (pFETs) are disposed in a semiconductor orientation which is optimal for hole mobility. This invention discloses that the performance advantages of FETs formed entirely in the optimal semiconductor orientation may be achieved by only requiring that the device's channel be disposed in a semiconductor with the optimal orientation. A variety of new FET structures are described, all with the characteristic that at least some part of the FET's channel has a different orientation than at least some part of the FET's source and/or drain. Hybrid substrates into which these new FETs might be incorporated are described along with their methods of making.