GALLIUM NITRIDE-BASED SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• Main Authors: TAKASHIMA SHINYA, MATSUYAMA HIDEAKI, TERANISHI HIDEAKI, TANAKA AKIRA, EDO MASAHARU, MORI DAISUKE, UENO KATSUNORI, INOUE CHIZURU, SUDA HIROTAKA
• Format: Patent
• Language: English; Japanese
• Published: 25.07.2019
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

To make clear the relation between a thickness of a transition layer and an electron field-effect mobility of a GaN-based semiconductor layer.SOLUTION: When the thickness of a transition layer is defined as (i) a distance between: a position of a depth on a gallium nitride-based semiconductor layer side, where if an atomic composition of a metal element included in an insulator layer has a maximum in an atomic composition distribution, the atomic composition of the metal element having the maximum becomes 1/2 of the maximum value, or a position of a depth where the atomic composition of the metal element having no maximum becomes 1/2 in a position sufficiently distant from the transition layer on an insulator layer side if the atomic composition of the metal element included in an insulator layer has no maximum; and a position of a depth where an atomic composition of a nitrogen element included in the GaN-based semiconductor layer becomes 1/2 in a deep position in a position sufficiently distant from the transition layer on a GaN-based semiconductor layer side, or (ii) a thickness of a layer provided in contact with the surface of the GaN-based semiconductor layer having a crystal structure, and determined with a contrast different from both of the GaN-based semiconductor layer and the insulator layer in a transmission electron microscope image, the thickness of the transition layer is less than 1.5 nm.SELECTED DRAWING: Figure 1 【課題】遷移層の厚さと、ＧａＮ系半導体層の電界効果移動度との関係は明らかにされていなかった。【解決手段】遷移層の厚さを、（ｉ）絶縁層を構成する金属元素の原子組成が原子組成分布において極大を有する場合は、極大を有する金属元素の原子組成が極大の値の１／２となる窒化ガリウム系半導体層側の深さ位置、もしくは、極大を有しない場合は、極大を有しない金属元素の原子組成が遷移層よりも絶縁層側に十分に離れた箇所に対して１／２となる深さ位置と、ＧａＮ系半導体層を構成する窒素元素の原子組成が、遷移層よりもＧａＮ系半導体層側に十分に離れた箇所に対して１／２となる深さ位置との間の距離、または、（ｉｉ）結晶構造を有するＧａＮ系半導体層の表面に接して設けられ、透過電子顕微鏡像におけるＧａＮ系半導体層および絶縁層の両方と異なるコントラストにより規定される層の厚さ、と定義するとき、遷移層の厚さは、１．５ｎｍ未満である。【選択図】図１