Method of forming a high-k crystalline dielectric

摘要

Provided are a method of forming a dielectric and a method of fabricating a semiconductor device. The method includes forming a preliminary dielectric including Hf, O and an “A” element on an underlying layer. The preliminary dielectric is formed in an amorphous structure or a mixed structure of an amorphous structure and an “M” crystalline structure. The “A” element about 1 at % to about 5 at % of the total content of the “A” element and Hf in the preliminary dielectric. Through a nitridation process, nitrogen is added to the preliminary dielectric. The nitrogen-containing dielectric is changed into a dielectric having a “T” crystalline structure through a phase transition process, wherein the “T” crystalline structure is different from the “M” crystalline structure. An upper layer is formed on the “T” crystalline dielectric.

主权项

1. A method of forming a dielectric, comprising:
forming a preliminary dielectric in an amorphous structure or in a mixed structure of an amorphous structure and a monoclinic crystalline structure, the preliminary dielectric including hafnium (Hf), oxygen (O), and an “A” element that comprises at least one of silicon (Si), yttrium (Y), gadolinium (Gd), aluminum (Al) and zirconium (Zr); forming a barrier HfSiO layer before or after forming the preliminary dielectric, wherein the barrier HfSiO layer is formed in an amorphous structure; performing a nitridation process on the preliminary dielectric and the barrier HfSiO layer to add nitrogen to the preliminary dielectric and the barrier HfSiO layer, forming a nitrogen-containing preliminary dielectric and a barrier HfSiON layer; and performing a phase transition process on the nitrogen-containing preliminary dielectric, phase-changing the nitrogen-containing preliminary dielectric into a crystalline dielectric having a tetragonal or cubic crystalline structure, wherein the barrier HfSiON layer maintains the amorphous structure during and after the phase transition process, and wherein the content of Si as a percentage of the total content of Hf and Si in the barrier HfSiO layer is higher than the content of the “A” element as a percentage of the total content of “Hf” and the “A” element in the preliminary dielectric layer.