Process for producing semiconductor article using graded epitaxial growth

Abstract

A process for producing monocrystalline semiconductor layers. In an exemplary embodiment, a graded Si1-xGex (x increases from 0 to y) is deposited on a first silicon substrate, followed by deposition of a relaxed Si1-yGey layer, a thin strained Si1-zGez layer and another relaxed Si1-yGey layer. Hydrogen ions are then introduced into the strained SizGez layer. The relaxed Si1-yGey layer is bonded to a second oxidized substrate. An annealing treatment splits the bonded pair at the strained Si layer, such that the second relaxed Si1-yGey layer remains on the second substrate. In another exemplary embodiment, a graded SixGex is deposited on a first silicon substrate, where the Ge concentration x is increased from 0 to 1. Then a relaxed GaAs layer is deposited on the relaxed Ge buffer. As the lattice constant of GaAs is close to that of Ge, GaAs has high quality with limited dislocation defects. Hydrogen ions are introduced into the relaxed GaAs layer at the selected depth. The relaxed GaAs layer is bonded to a second oxidized substrate. An annealing treatment splits the bonded pair at the hydrogen ion rich layer, such that the upper portion of relaxed GaAs layer remains on the second substrate.

Description

PRIORITY INFORMATION [0001] This application claims priority from provisional application Ser. No. 60 / 225,666 filed Aug. 16, 2000.BACKGROUND OF THE INVENTION [0002] The present invention relates to a production of a general substrate of relaxed Si1-xGex-on-insulator (SGOI) for various electronics or optoelectronics applications, and the production of monocrystalline III-V or II-VI material-on-insulator substrate. [0003] Relaxed Si1-xGex-on-insulator (SGOI) is a very promising technology as it combines the benefits of two advanced technologies: the conventional SOI technology and the disruptive SiGe technology. The SOI configuration offers various advantages associated with the insulating substrate, namely reduced parasitic capacitances, improved isolation, reduced short-channel-effect, etc. High mobility strained-Si, strained-Si1-xGex or strained-Ge MOS devices can be made on SGOI substrates. [0004] Other III-V optoelectronic devices can also be integrated into the SGOI substrate by...

AI Technical Summary

Benefits of technology

[0010] According to the invention, there is provided an improved technique for production of wide range of high quality material is provided. In particular, the production of relaxed Si1-xGex-on-insulator (SGOI) substrate or relaxed III-V or II-VI material-on-insulator, such as GaAs-on-insulator, is described. High quality monocrystalline relaxed SiGe layer, relaxed Ge layer, or other relaxed III-V material layer is grown on a silicon substrate using a graded Si1-xGex epitaxial growth technique. A thin film of the layer is transferred into an oxidized handle wafer by wafer bonding and wafer splitting using hydrogen ion implantation. The invention makes use of the graded Si1-xGex buffer structure, resulting in a simplified and improved process.

[0011] The invention also provides a method allowing a wide range of device materials to be integrated into the inexpensive silicon substrate. For example, it allows production of Si1-xGex-on-insulator with wide range of Ge concentration, and allows production of many III-V or II-VI materials on insulator like GaAs, AlAs, ZnSe and InGaP. The use of graded Si1-xGex buffer in the invention allows high quality materials with limited dislocation defects to be produced and transferred. In one example, SGOI is produced using a SiGe structure in which a region in the graded buffer can act as a natural etch stop.

Problems solved by technology

One of the main drawbacks is the quality of the resulting Si1-xGex film and BOX.

In addition, Ge segregation during high temperature anneal also limits the maximum Ge composition to a low value.

The silicon layer in the structure is unnecessary, and may complicate or undermine the performance of devices built on it.

For example, it may form a parasitic back channel on this strained-Si, or may confine unwanted electrons due to the band gap offset between the strained-Si and SiGe layer.

The presence of the silicon layer in the above structure may be for the purpose of facilitating Si-insulator wafer bonding, but is unnecessary for ideal SGOI substrates.

Again, the silicon layer may also complicate or undermine the performance of devices built on it.

For example, it may form a parasitic back channel on this strained-Si, or may confine unwanted electrons due to the band gap offset between the strained-Si and SiGe layer.

Moreover, the etch stop of Pa in the above structure is not practical when the first graded Si1-yGey layer described in the patents has a y value of larger than 0.2.

Therefore, the KOH will not be able to remove the first graded SityGey layer and the second relaxed SiGe layer as described in the patents.

Other attempts include re-crystallization of an amorphous Si1-xGex layer deposited on the top of SOI (silicon-on-insulator) substrate, which is again not an ideal SGOI substrate and the silicon layer is unnecessary, and may complicate or undermine the performance of devices built on it.

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