Preparation method of low leakage current HfO2 film suitable for gate dielectric layer

Abstract

The invention relates to a semiconductor technology, and provides a preparation method of a low leakage current HfO2 film suitable for a gate dielectric layer, which solves the problem that preparation processes of existing HfO2 gate dielectric film materials are unfavourable for large-scale preparation of films. The preparation method comprises the following steps: firstly putting a silicon substrate into a vacuum chamber base after the surface of the silicon substrate is cleaned and a natural oxidation layer on the surface is removed, secondly putting a metal hafnium target with surface polished and cleaned into a target position in a vacuum chamber as a target, closing a target baffle, utilizing high vacuum multifunctional radio frequency sputtering coating equipment to vacuumize the vacuum chamber, carrying out backwash cleaning on the substrate, switching on a radio frequency power supply and adjusting the power of the radio frequency power supply after backwash cleaning, carrying out pre-sputtering, finally adjusting the argon flux, opening the target baffle, pre-depositing an ultra-thin hafnium film and filling oxygen to formally sputter a hafnium dioxide film, thus forming the hafnium dioxide film. The preparation method has the beneficial effects that the preparation method is convenient for large-scale preparation and is suitable for MOS (metal oxide semiconductor) capacitors.

Description

technical field

[0001] The present invention relates to semiconductor technology, in particular to high dielectric constant HfO 2 (HfO2) thin film. Background technique

[0002] With the continuous increase of VLSI integration, the size of metal oxide semiconductor (MOS) devices, which are the main components of integrated circuits, has been continuously reduced, and the thickness of the gate oxide layer has also been continuously reduced. When conventional SiO 2 (Silicon dioxide) When the thickness of the gate oxide layer is as small as its threshold value (about 2-3nm), the high electric field strength of the oxide layer will cause problems such as direct tunneling, resulting in a sharp increase in leakage current, thereby affecting the stability of the device and even affect its normal operation. In order to reduce the gate leakage of ultra-thin gate dielectric MOS devices, high dielectric constant (high K) gate dielectrics can be used instead of SiO 2 . According to...

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