Integrated Schottky Diode in CMOS
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
An integrated Schottky barrier diode (SBD) is created in either the source or drain diffusion of an n-channel metal oxide semiconductor field-effect transistor (MOSFET). No additional masking step is required. The integrated SBD is formed by conventional processing through definition of the polysilicon gate lines 2, as shown in Fig. 1. An arsenic (As) ion beam exposure of the entire wafer results in the lightly doped, n- implanted regions 4 and 6. The region 6 ultimately becomes the SBD or lightly doped drain region. Following subsequent conventional processing, i.e., spacer 8 definition, a blocking mask 10 protects the lightly doped drain region 6 (as well as any p-channel device regions) while the source region 4 is highly doped (n+) by another As ion implant, as shown in Fig. 2.