Ultrashallow junctions for ULSI using As/sub 2//sup +/ implantation and rapid thermal anneal

Using As/sub 2//sup +/ ion implantation and rapid thermal anneal, 40-nm n/sup +/-p junctions are realized. The junction formed with p/sup -/ substrate shows very low leakage current (<0.5 nA/cm/sup 2/) up to 2-V reverse bias. The introduction of a heavily doped (10/sup 18/ cm/sup -3/ level) p region generates a significantly higher leakage current due to the onset of band-to-band tunneling. Using varied geometry devices with a given area, the major tunneling current is shown to be confined in the perimeter of the device, and a method to suppress this leakage is suggested.<
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