Peking University

Yuancheng Yang

Ru Huang

Jiewen Fan

Hao Zhang

Li Wang

Haoran Xuan

Gong Chen

Hanming Wu

Weihai Bu

Ming Li

The present invention discloses a method for integrating a vertical nanowire transistor and belongs to a field of field effect transistor logic device in a CMOS ultra-large scale integrated circuit (ULSI). The method realizes the integration of the vertical-nanowire transistor by combining selective epitaxy and replacement gate on sidewall. In comparison with an existing method for forming a vertical nanowire channel by etching, a size and shape of a cross section of a device channel can be accurately controlled, a consistency of device characteristic can be improved, and an etching damage during the forming of a channel in the existing method can be avoided, thereby the device performance can be improved.

Integration method for a vertical nanowire transistor

A method for fabricating multiple layers of ultra narrow silicon wires comprises the steps of fabricating wet-etch masking layers of silicon; forming a Fin and source/drain regions located at both ends thereof by epitaxy; forming the multiple layers of ultra narrow silicon wires. The present invention has advantages in that: the atom layer depositing may define the position of the ultra narrow silicon wires accurately, having a good controllability; the anisotropic wet-etch for silicon is performed in a self-stop manner and has a large process window, so that the cross-section shape of the nanowires formed by wet-etch is uniform and smooth. The method to form multiple layers of wet-etch masks at the sidewalls of Fins, in which wet-etch masking layers are formed prior to the epitaxy of Fins is a simple process, so that the multiple sidewall wet-etch masking layers may be obtained by only one etching to the epitaxy window, regardless of the numbers of the wet-etch masking layers; a wire with a diameter less than 10 nm may be fabricated by virtue of the oxidation technology, and thus satisfies the small size devices; the TMAH solution, which is simple and safe to control, is used in the wet-etch for polysilicon, and metal ions are not introduced and thus suitable for the integrated circuit manufacturing process; the method according to the present invention is fully compatible with the planar transistor based on the bulk silicon, and thus the process cost is small.

Method for fabricating multiple layers of ultra narrow silicon wires

The present invention discloses a method for fabricating a quasi-SOI source/drain field effect transistor device, which comprises the steps of forming an active region of the device; forming a gate stack structure of the device; doping a source/drain extension region, and forming a first layer of side wall at two sides of the gate stack structure; forming a recessed source/drain structure; forming a quasi-SOI source/drain isolation layer; in-situ doping an epitaxial second semiconductor material source/drain, and activating by annealing; removing the previous dummy gate and re-depositing a high-k metal gate, if a post-gate process is employed; and forming contacts and metal interconnections. The method of the invention is well compatible with the existing CMOS process, and it has the features of simple process and small heat budget; and in comparison with the traditional field effect transistor, by means of the quasi-SOI source/drain field effect transistor device fabricated according to the method of the invention, the leakage current can be lowered effectively, thus the power consumption of the device can be reduced.

Method for fabricating quasi-SOI source/drain field effect transistor device

Growing community of inventors

Beijing, China

Yuancheng Yang