High-K gate dielectric layer formation method and semiconductor device

Abstract

The invention provides a high-K gate dielectric layer formation method and a semiconductor device. The method comprises the following steps: providing a semiconductor substrate, a dielectric layer being formed on the semiconductor substrate, and a gate opening being formed in the dielectric layer; and depositing a high-K material layer, wherein the high-K material layer covers the bottom portion and side wall of the gate opening, and the high-K material layer is made of the mixture of HfO2 and ZrO2. The method helps to improve the film quality of a high-K gate dielectric layer, and helps to form the high-K gate dielectric layer having higher K value and thinner equivalent oxide layer thickness.

Description

Technical field [0001] The invention relates to a semiconductor device and semiconductor process technology, in particular to a method for forming a high-K gate dielectric layer and a semiconductor device. Background technique [0002] When the high-k gate dielectric metal gate process (HKMG) first appeared, ZrO 2 Because of its high dielectric constant (K) and low transition temperature from amorphous to crystalline, it has received extensive attention. However, using ZrO 2 It has the following disadvantages: ZrO at higher processing temperature 2 It is not stable with silicon. [0003] HfO 2 The dielectric constant is about 20, and it is refractory enough under normal silicon processing conditions and will not react with the silicon substrate or the polysilicon electrode on it. Therefore, the existing technology currently usually uses HfO 2 To form a high-K gate dielectric layer. [0004] figure 1 with figure 2 The formation process of a high-K gate dielectric layer in the prior...

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Problems solved by technology

However, using ZrO 2 Has the following disadvantages: at higher processing temperatures ZrO 2 not stable with silicon

[0008] However, the high-K gate dielectric layer formed by the above method has many disadvantages, such as poor film quality and thick equivalent oxide thickness (EOT) due to its insufficient K value.

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