Method for fabricating saddle type fin transistor

Abstract

A method for fabricating a saddle type fin transistor includes: preparing a substrate where a device isolation structure is already formed; forming a hard mask pattern over the substrate, the hard mask pattern including a coating layer obtained through a coating method; and performing an etching process using the hard mask pattern as an etch mask to form a saddle type fin. The hard mask pattern may be formed in a stack structure including an amorphous carbon layer and the coating layer.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for fabricating a semiconductor device; and more particularly, to a method for fabricating a saddle type fin transistor having characteristics of a fin transistor and a recess transistor. DESCRIPTION OF RELATED ARTS [0002] Generally, transistors having horizontal channels that are most widely used often have disadvantages associated with a current trend in the large-scale of device minimization and integration. Thus, the minimization of such transistors becomes limited. The minimized horizontal channels of the transistors may have disadvantages such as a short channel effect and a drain induced barrier lower (DIBL) effect, usually caused by a shortened channel length. If the channel length is decreased to 50 nm or less, process variations increase, resulting in scattered device characteristics. If the channel length is decreased to 30 nm or less, the short channel effect and the DIBL effect become severe, often ...

AI Technical Summary

Benefits of technology

The present invention provides a method for making a saddle type fin transistor that reduces the FICD (floating body effect) caused by a height difference between an active region and a field region, which improves device performance. The method includes preparing a substrate with a device isolation structure, forming a hard mask pattern over the substrate, and using the hard mask pattern as an etch mask to form a saddle type fin.

Problems solved by technology

Generally, transistors having horizontal channels that are most widely used often have disadvantages associated with a current trend in the large-scale of device minimization and integration.

Thus, the minimization of such transistors becomes limited.

The minimized horizontal channels of the transistors may have disadvantages such as a short channel effect and a drain induced barrier lower (DIBL) effect, usually caused by a shortened channel length.

If the channel length is decreased to 30 nm or less, the short channel effect and the DIBL effect become severe, often disabling a normal device operation.

Thus, an electric field that has an upward / downward unbalance is more likely to be applied to the horizontal channels, and as a result, controlling an on / off operation of the transistors is generally difficult due to the gate electrodes.

However, this fin structure is generally limited to increase an effective channel length despite the reduction in a body effect.

Thus, it may be difficult to achieve an overlap between the device isolation structure Fox and the corresponding gate Gate.

This difficulty may result in generation of bridges between the gates, or leakage current during formation of contacts, thereby degrading device characteristics.

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