Semiconductor structure and method for forming semiconductor structure

Abstract

The invention provides a semiconductor structure and a method for forming the semiconductor structure. The method comprises a step of providing a substrate and fins protruding from the substrate, wherein the materials of the fins contain germanium elements, an isolation layer covering partial sidewalls of the fins are on the substrate, and the top of the isolation layer is lower than the tops of the fins, a step of forming a dummy gate oxide layer on the tops and sidewalls of the fins exposed by the isolation layer by using the atomic layer deposition process, wherein the process temperature of the atomic layer deposition process is a first temperature, a step of forming a dummy gate across the fins, wherein the dummy gate covers the surface of a dummy gate oxide layer, a step of forming adielectric layer on the isolation layer, wherein the dielectric layer covers a sidewall of the dummy gate and exposes a top wall of the dummy gate, a step of removing the dummy gate and the dummy gate oxide layer and exposing the tops and partial sidewalls of the fins, and a step of forming an interface layer on the exposed tops and sidewalls of the fins, wherein the process temperature of forming the interface layer is a second temperature which is lower than or equal to the first temperature. According to the invention, the germanium elements in the fins can be prevented from diffusing intothe interface layer, therefore, the interface characteristics between the interface layer and the fins can be improved, and the carrier mobility is enhanced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] Carrier mobility is a measure of the overall movement of electrons and holes within a semiconductor structure. The carrier mobility has an important influence on the electrical properties of the semiconductor structure: on the one hand, the carrier mobility determines the conductivity of the semiconductor material, the greater the carrier mobility, the greater the conductivity, so when the same current passes through , the smaller the power consumption. On the other hand, the carrier mobility affects the operating frequency of the semiconductor structure. The greater the carrier mobility, the shorter the time for carriers to cross the base region, so the frequency response characteristics of the semiconductor structure are more excellent. [0003] Studies have found that co...

AI Technical Summary

Problems solved by technology

[0004] However, despite the introduction of germanium in the channel material, the performance of semiconductor structures still needs to be improved

Images