Tunneling metal - semiconductor devices with adjustable barrier height and width, fabricated with GaAs molecular layer epitaxy and W CVD

The advantage of a very thin mixed layer at the interface of W deposited from W(CO)₆ on GaAs, was exploited for fabrication of tunneling metalsemiconductor diodes. The effective potential barrier height and width can be adjusted with the thickness and dopant concentration in the thin layer below W. The W/p⁺⁺/n⁺⁺ diodes with 60 - 80 Å p⁺⁺ layer operate with electrons tunneling through the depleted p⁺⁺ layer. The W/n⁺⁺/n-/n diode works like a series connection of a tunneling contact and a Schottky barrier diode with the effective barrier height controlled in a wide range. These structures, fabricated with molecular layer epitaxy, can find application as building blocks of tunneling static induction transistors (SIT) and TUNNETT diodes and as low voltage drop GaAs diodes.