| 摘要 |
PURPOSE:To obtain an ohmic contact with good surface condition, high mechanical strength and a low resistance by forming, on the surface of a first metal layer consisting of alloy, a second metal layer which is composed of an element of the same kind as said alloy with concentration thereof being added is lower than said alloy and thereafter heating it for reaction with semiconductor substrate for obtaining the alloy. CONSTITUTION:A first metal layer 3 consisting of an alloy of AuGe (with concentration of Ge of 12%) is formed in the thickness of 500Angstrom on the surface of a GaAs semiconductor substrate 1 and then a second metal layer 4 consisting of an alloy of AuGe (with concentration of Ge of 10%) is also formed thereon in the thickness of 1,200Angstrom . Thereafter, these are alloyed under the ambient of H2 at 470 deg.C. At this time, the temperature is raized up to 470 deg.C in the alloying reaction during three minutes. When temperature reaches 470 deg.C, it is immediately be lowered up to 100 deg.C during three minutes. After the reaction for alloying, an Mo metal layer 9 is formed as the barrier metal and then an Au electrode 10 is also formed thereon. Thereby, a compound semiconductor device having the ohmic contact of a low resistance is obtained. |
