Electrode for semiconductor chip and semiconductor chip with the electrode
View Patent ↗In an n-type semiconductor layer that contains gallium (Ga), contact resistance is to be suppressed at a low level. An n-side electrode is provided on a surface of the n-type semiconductor layer containing Ga. The electrode includes a metal layer having a Ga content of equal to or more than 1 at % and equal to or less than 25 at %. The metal layer is disposed in contact with the n-type semiconductor layer.
1. A semiconductor laser, comprising:
an n-side electrode to be formed on a surface of an n-type semiconductor layer that comprises gallium (Ga),
wherein said n-side electrode comprises:
a metal layer having a Ga content of equal to or more than 1 at% and equal to or less than 10 at%,
wherein said metal layer is disposed in contact with said n-type semiconductor layer, and
wherein a metal predominantly composing said metal layer is Ti.
2. The semiconductor laser according to claim 1 , wherein said metal layer includes a metal material having a Ga content of equal to or more than 1 at% and equal to or less than 10 at%.
3. The semiconductor laser according to claim 1 , wherein said n-type semiconductor layer includes a III-V compound.
4. The semiconductor laser according to claim 1 , wherein said metal predominantly composing said metal layer has a work function of equal to or less than 5 eV.
5. The semiconductor laser according to claim 1 , wherein said n-type semiconductor layer is an n-type nitride semiconductor layer.
6. The semiconductor laser according to claim 1 , wherein said n-side electrode further comprises a gold-plating layer disposed above the metal layer.
7. The semiconductor laser according to claim 6 , wherein said n-side electrode further comprises a barrier layer disposed between the gold-plating layer and the metal layer.
8. The semiconductor laser according to claim 6 , wherein said n-side electrode further comprises a gold layer and a platinum layer disposed between the gold-plating layer and the metal layer.
9. The semiconductor laser according to claim 1 , wherein said n-type semiconductor layer comprises Ti 3 Ga or Ti 2 Ga.
10. A recording and reproducing apparatus, comprising a semiconductor laser according to claim l.
11. The semiconductor laser according to claim 1 , wherein a thickness of the metal layer is 100 Å or more.