Transfer of Single Crystalline Silicon Nanolayer Onto Alien Substrate

Abstract

Starting from the 60-nm node, future generations of mainstream semiconductor devices (i.e., CMOS) will be mostly manufactured from silicon-on-insulator (SOI) initial substrates with the top silicon layer having a thickness 50 nm or less. We describe a process that is capable for transfer of nanoscale thick layers. The layer is delaminated from a single crystalline silicon substrate and laminated onto another substrate, thus resulting in SOI. The process includes: 1) forming a trap layer for hydrogen in an initial substrate; 2) delivery of hydrogen to the traps by diffusion of monatomic hydrogen; 3) evolving the trapped hydrogen into a layer of hydrogen platelets; 4) stiffening of the surface of the initial substrate by laminating to another substrate; and 5) delaminating a layer from the initial substrate along the hydrogen platelet layer. Details of the new layer transfer process are described. A depth where the buried trap layer locates is critical for the process. An implantation of heavy ions is used to form the trap layer. A trap capacity for hydrogen is evaluated as a function of implantation conditions. Plasma hydrogenation is used to deliver atomic hydrogen to the traps. Electron cyclotron resonance, microwave, RF, and dc plasma are compared as the hydrogenation sources. Dependence of a thickness of a transferred layer as a function of the mass of implanted ions and implantation energy is described. Types of layer transfer faults are also described. Mechanisms of the layer transfer faults are suggested. We discuss limits of scaling down of the thickness of the layer that is transferred from one substrate to another. The scaling limit of our process is compared to the limits of other (SIMOX, Smart-Cut, and ELTRAN) processes.

Two-dimensional phonon hydrodynamics in narrow strips

“…In recent years, several research groups have focused their attention on the contribution of collective hydrodynamiclike phonon behaviour on two-dimensional nanosystems [1][2][3][4]. Silicon nanolayers, boron nitride nanolayers [5][6][7] and graphene [8][9][10] have especially attracted attention. In particular, it has been recently argued that, in suspended graphene [4] and other two-dimensional systems [3], Poiseuille phonon flow could be observed at higher temperatures and in wider temperature ranges than in three-dimensional systems, because in two-dimensional systems the normal (momentum conserving) phonon-phonon collisions are two orders of magnitude higher than those in three-dimensional systems.…”