Peking University

Yujie Ai

Ru Huang

Runsheng Wang

Jiewen Fan

Xin Huang

Shuai Sun

Jibin Zou

Zhihua Hao

Shuangshuang Pu

Jing Zhuge

Xiaoyan Xu

Quanxin Yun

Gengyu Yang

Shoubin Xue

Chunhui Fan

Disclosed herein is a method for fabricating a silicon nanowire field effect transistor based on a wet etching. The method includes defining an active region; depositing a silicon oxide film as a hard mask, forming a pattern of a source and a drain and a fine bar connecting the source and the drain; transferring the pattern on the hard mask to a silicon substrate by performing etching process for the silicon substrate; performing ion implanting; etching the silicon substrate by wet etching, so that the silicon fine bar connecting the source and the drain is suspended; reducing the silicon fine bar to a nano size to form a silicon nanowire; depositing a polysilicon film; forming a polysilicon gate line acrossing the silicon nanowire by electron beam lithography and forming a structure of nanowire-all-around; forming a silicon oxide sidewall at both sides of the polysilicon gate line, by depositing a silicon oxide film and subsequently etching the silicon oxide film; forming the source and the drain by using ion implantation and high temperature annealing, so that the silicon nanowire field effect transistor is finally fabricated. The method is compatible with a conventional integrated circuit fabrication technology. The fabrication process is simple and convenient, and has a short cycle.

Method for fabricating silicon nanowire field effect transistor based on wet etching

Disclosed herein is a field effect transistor with a vertical channel and a fabrication method thereof. A channel region of the field effect transistor is a circular ring-shaped Si platform, which is formed over a substrate and perpendicular to the substrate; a source, which is made of polysilicon, is located at an upper end of the Si platform; a drain is disposed at an outside of a lower end of the circular ring-shaped Si platform; a gate is placed on an outer side surface of the circular ring-shaped Si platform; and an inside of the circular ring-shaped Si platform is filled with a dielectric material. In comparison with the conventional vertical structure MOSFET with a Si platform, the circular ring-shaped structure field effect transistor according to the invention can effectively suppress the short channel effect and improve the device performance.

Field effect transistor with a vertical channel and fabrication method thereof

The present invention discloses a heat dissipation structure for a SOI field effect transistor having a schottky source/drain, which relates to a field of microelectronics. The heat dissipation structure includes two holes connected with a drain terminal or with both a source terminal and a drain terminal, which are filled with an N-type material with high thermoelectric coefficient and a P-type material with high thermoelectric coefficient respectively. A metal wire for the N-type material with high thermoelectric coefficient in the vicinity of the drain terminal is applied a high potential with respect to the drain terminal, and a metal wire for the P-type material with high thermoelectric coefficient in the vicinity of the drain terminal is applied a low potential with respect to the drain terminal. A metal wire for the N-type material with high thermoelectric coefficient in the vicinity of the source terminal is applied a high potential with respect to the source terminal, and a metal wire for the P-type material in the vicinity of the source terminal is applied a lower potential with respect to the source terminal. By way of a Peltier effect, in the present invention heat can be absorbed at a contact portion between the thermoelectric material and the source/drain, and at the same time dissipated at a connection portion between the thermoelectric material and a bottom electrode metal, so that the heat generated in an active region of the device is effectively transferred to the substrate and dissipated through a heat sink.

Heat dissipation structure of SOI field effect transistor

The present invention discloses a fabrication method of a vertical silicon nanowire field effect transistor having a low parasitic resistance, which relates to a field of an ultra-large-integrated-circuit fabrication technology. As compared with a conventional planar field effect transistor, on one hand the vertical silicon nanowire field effect transistor fabricated by the present invention can provide a good ability for suppressing a short channel effect due to the excellent gate control ability caused by the one-dimensional structure, and reduce a leakage current and a drain-induced barrier lowering (DIBL). On the other hand, an area of the transistor is further reduced and an integration degree of an IC system is increased.

Fabrication method of vertical silicon nanowire field effect transistor

The invention provides a high voltage-resistant lateral double-diffused transistor. The lateral double-diffused MOS transistor includes a channel region, a gate dielectric, a gate region, a source region, a drain region, a source end extension region and a drain end S-shaped drifting region, wherein the channel region has a lateral cylindrical silicon nanowire structure, on which a layer of gate dielectric is uniformly covered, the gate region is on the gate dielectric, the gate region and the gate dielectric completely surround the channel region, the source end extension region lies between the source region and the channel region, the drain end S-shaped drifting region lies between the drain region and the channel region, the plan view of the drain end S-shaped drifting region is in the form of single or multiple S-shaped structure(s), and an insulating material with a relative dielectric constant of 1-4 is filled within the S-shaped structure(s).

High voltage-resistant lateral double-diffused transistor based on nanowire device

A method for fabricating a surrounding-gate silicon nanowire transistor with air sidewalls is provided. The method is compatible with the CMOS process; the introduced air sidewalls can reduce the parasitic capacitance effectively and increase the transient response characteristic of the device, thus being applicable to a high-performance logic circuit.

Method for fabricating surrounding-gate silicon nanowire transistor with air sidewalls

The invention discloses a fabrication method for a surrounding gate silicon nanowire transistor with air as spacers. The method comprises: performing isolation, and depositing a material A which has a higher etch selectivity ratio with respect to Si; performing photolithography to define a Fin hard mask; etching the material A to form the Fin hard mask; performing source and drain implantation; performing photolithography to define a channel region and large source/drain regions; forming the Si Fin and the large source/drains; removing the hard mask of the material A; forming a nanowire; etching the SiOto form a floating nanowire; forming a gate oxide layer; depositing a polysilicon; performing polysilicon injection; performing annealing to activate dopants; etching the polysilicon; depositing SiN; performing photolithography to define a gate pattern; etching the SiN and the polysilicon to form the gate pattern; separating the gate and the source/drain with a space in between filled with air; depositing SiOto form air sidewalls; performing annealing to densify the SiOlayer; using subsequent processes to complete the device fabrication. The invention is compatible with the CMOS process flow. The introduction of the air sidewalls can effectively reduce the parasitic capacitance of the device, and improve the transient response of the device, so that the method is applicable for a logic circuit with high performance.

Fabrication method for surrounding gate silicon nanowire transistor with air as spacers

The present invention discloses a method for self-alignedly fabricating tunneling field-effect transistor (TFET) based on planar process, thereby lowering requirements on a photolithography process for fabricating the planar TFET. In the method, the source region and the drain region of the TFET are not directly defined by photolithography; rather, they are defined by another dielectric film which locates over an active region and on both sides of the gate and which is different from the dielectric film that defines the channel region. The influence due to the alignment deviation among three times of photolithography process for defining the channel region, the source and the drain regions may be eliminated by selectively removing the dielectric film over the source and drain regions by wet etching. Therefore, a planar TFET may be fabricated self-alignedly based on this process, thereby the rigid requirements on the alignment deviation of the photolithography during the fabrication procedure of a planar TFET is alleviated, which facilitates to fabricate a planar TFET device with stable and reliable characteristics.

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Beijing, China

Yujie Ai