Transistor and forming method thereof

Abstract

The invention provides a transistor and a forming method thereof. The forming method comprises: a base including a substrate, a stress constraint layer and a channel layer are provided, wherein the stress constraint layer and the channel layer are arranged on the surface of the substrate successively; a gate structure is formed on the base; the channel layer at the two sides of the gate structure are removed and grooves are formed in the sidewall of the remaining channel layer; the stress constraint layer at the two sides of the gate structure is removed and the base at the two sides is removed with a certain thickness to form a first opening; and the first opening is filled to form a stress layer. Because the stress constraint layer is arranged in the base, the stress layer arranged at the two sides of the gate in the base has a part having a protrusion in the channel layer and a part in the stress constraint layer and the substrate. The protrusion of the stress layer in the channel layer enables stresses to be led into a channel in the channel layer; the stress layer in the stress constraint layer and the substrate enables the size of the stress layer to be increased, so that the stress of the channel region can be increased. Therefore, the migration rate of carriers in the channel can be improved, so that the transistor performance can be improved.

Description

technical field [0001] The present invention relates to the field of semiconductor manufacturing, in particular to a transistor and a method for forming the same. Background technique [0002] As the most basic semiconductor device, transistors are being widely used. With the increase in the density and integration of components in integrated circuits, the size of transistors is getting smaller and smaller. As transistor size shrinks, transistor channel length and gate length also shorten. The shortening of the channel length of the transistor makes the approximation of the graded channel no longer tenable, causing the short channel effect, which in turn generates leakage current and affects the performance of the semiconductor device. By introducing stress to the channel region of the transistor, the mobility of carriers in the channel can be improved, thereby increasing the driving current of the transistor, thereby suppressing the leakage current of the transistor. [...

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Problems solved by technology

[0004] However, the carrier mobility in the channel region of the transistor in the prior art is still low, which cannot better improve the performance of the semiconductor device.

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