17:15 〜 17:30
▲ [13p-D419-13] Effects of Polishing Damage on β-Ga2O3 Schottky Diodes Electrical Properties
キーワード：Ga2O3, Wide bandgap semiconductors, Schottky diodes
Beta gallium oxide (β-Ga2O3) is one of the most attractive ultra-wide bandgap semiconductors for power applications because of its outstanding intrinsic properties such as a high breakdown field of about 8 MV/cm and the commercially available large size substrates. Nowadays, the achievement of electronic grade β-Ga2O3 substrates with low defects density is still a very important issue. β-Ga2O3 crystals are grown by various methods, including Floating zone (FZ) method that allow a better control of doping density and reduction defects density. On the other hand, the implementation of β-Ga2O3 devices required a substrate polishing step that may induce surface and sub-surface defects. Thus far, the effects of such substrate polishing damages on β-Ga2O3 devices have not been investigated yet.
In this work, the effect of chemical-mechanical polishing (CMP) damage on vertical β-Ga2O3 Schottky diodes electrical properties are discussed. Basic Schottky diodes have been fabricated on FZ β-Ga2O3 substrates. The substrates growth was followed by a CMP polishing that induced surface damage. Different Schottky metals, Aluminium (Al), Platinum (Pt), and Ruthenium (Ru) with Gold (Au) cap-layers were then deposited (on front side to achieve vertical Schottky diode). The fabricated Schottky diodes exhibited good rectification behaviours even at high temperature. A rectification ratio of about 9 order of magnitudes was measured from a bias ranging from –10 to 10 V. The typical Schottky barrier height and ideality factor are 1.22 eV and 1.3, respectively. It has been found that (Pt/Au) and (Ru/Au) contacts showed a Schottky behaviour whereas (Al/Au) contacts were ohmic. The transport mechanism, the device reproducibility, and the effects of Schottky metals on diodes electrical performance will be discussed.
In this work, the effect of chemical-mechanical polishing (CMP) damage on vertical β-Ga2O3 Schottky diodes electrical properties are discussed. Basic Schottky diodes have been fabricated on FZ β-Ga2O3 substrates. The substrates growth was followed by a CMP polishing that induced surface damage. Different Schottky metals, Aluminium (Al), Platinum (Pt), and Ruthenium (Ru) with Gold (Au) cap-layers were then deposited (on front side to achieve vertical Schottky diode). The fabricated Schottky diodes exhibited good rectification behaviours even at high temperature. A rectification ratio of about 9 order of magnitudes was measured from a bias ranging from –10 to 10 V. The typical Schottky barrier height and ideality factor are 1.22 eV and 1.3, respectively. It has been found that (Pt/Au) and (Ru/Au) contacts showed a Schottky behaviour whereas (Al/Au) contacts were ohmic. The transport mechanism, the device reproducibility, and the effects of Schottky metals on diodes electrical performance will be discussed.