Peking University

Zhihua Hao

Ru Huang

Runsheng Wang

Shuangshuang Pu

Jiewen Fan

Yujie Ai

Shuai Sun

Xia An

Xiaoyan Xu

Quanxin Yun

Yujie Al

Chunhui Fan

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 method for fabricating a semiconductor nano circular ring. In the method, firstly, a positive photoresist is coated on a semiconductor substrate, then the photoresist is exposed by using a circular mask with a micrometer-sized diameter to obtain the circular ring-shaped photoresist, based on the poisson diffraction principle. Then, a plasma etching is performed on the substrate under a protection of the circular ring-shaped photoresist to form a circular ring-shaped structure with a nano-sized wall thickness on a surface of the substrate. The embodiment of present invention fabricates a nano-sized circular ring-shaped structure by using a micrometer-sized lithography equipment and a micrometer-sized circular mask, and overcomes the dependence on advanced technologies, so as to effectively reduce the fabrication cost of the circular ring-shaped nano structure.

Method for fabricating semiconductor nano circular ring

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.

Method for fabricating a tunneling field-effect transistor

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Beijing, China

Zhihua Hao