High-k gate dielectric material and preparation method thereof

Abstract

The invention discloses a high-k gate dielectric material and a preparation method thereof, belonging to the technical field of semiconductors, in particular to the application field of metallic oxide semiconductor field effect transistors (MOSFET). The high-k gate dielectric material is a composite material of Er2O3-Al2O3 (ErAlO); an ErAlO amorphous grate dielectric composite oxide film is prepared on a P-type Si (100) substrate by an RF magnetron sputtering preparation method by a sputtering target which is a mixed ceramic target of Er2O3 and Al2O3; according to tests, the ErAlO film has favorable thermostability and planeness as well as low leakage current density and can replace SiO2 to become a novel high-k gate dielectric material.

Description

technical field [0001] The invention belongs to the field of semiconductors, in particular to the application field of metal oxide semiconductor field-effect transistors (MOSFETs), in particular to a high-k gate dielectric material and a preparation method thereof. The invention uses radio frequency magnetron sputtering to prepare amorphous Er2O3 - Al2O3 (ErAlO) high-K gate dielectric composite oxide film. The present invention provides a substitute for SiO 2 A new high-k gate dielectric candidate material, and its preparation method is provided. Background technique [0002] With the reduction of transistor feature size in integrated circuits, the current field effect transistor gate dielectric SiO 2 The thickness has been reduced to the nanometer level. At this time, affected by the tunneling effect, the gate leakage current will increase exponentially with the decrease of the thickness of the oxide layer, which becomes a problem that cannot be ignored. One of the solu...

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Problems solved by technology

Growth of high-k Er on Si substrate 2 o 3 Thin films have been reported by some research groups [8], but Er 2 o 3 High-k gate dielectric materials should successfully replace SiO in microelectronics processes 2 Film, Er 2 o 3 The thermal stability of the film needs to be improved, Chen[9] reported Er 2 o 3 The crystallization temperature of the film is relatively low (500-600°C). When the film changes from the original amorphous state to polycrystalline, it will cause the disadvantages of increased leakage current and increased diffusion of impurities along the grain boundary.

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