Edmund Burke

Skyworks Solutions, Inc.
  • The Effect of Delay Between Pre-clean and Metal Deposition on the Forward Current Voltage Characteristics of Schottky Devices

    Eric Finchem, MACOM
    Debdas Pal, MACOM Technology
    Lorain Ross, Skyworks Solutions, Inc.
    Sean Doonan, Skyworks Solutions, Inc.
    Edmund Burke, Skyworks Solutions, Inc.

    Schottky devices play an important role in modern electronics. The forward biased current-voltage characteristics of such devices are linear on a semi-logarithm scale at intermediate bias voltages. However, the curve deviates from linearity at higher voltage primarily due to series resistance. The applied forward voltage on the device is equal to the sum of the voltage drops across the (1) junction, (2) series resistance, (3) depletion layer and (4) any parasitic resistive layer between the Schottky metal and the semiconductor. Therefore, the interface between the metal and the semiconductor plays an important role in determining the critical parameters of Schottky devices. In this investigation a controlled delay was introduced between the pre-metal clean and Schottky metal deposition steps of the fabrication process to study the effects of naturally grown oxide on the forward characteristics of the Schottky devices.  The results of the investigation indicate such delays cause significant increases in series resistance and ideality factor, as well as a decrease in barrier height.

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