Abstract: A method of making a Zener diode having a Zener voltage in the range of 2.4-3.3 volts. The PN junction is preferably formed by selective epitaxial deposition of P-type silicon on a previously oxidized N-type silicon wafer in an opened region where the oxide has been etched away. The N-type wafer may be a uniform silicon wafer with resistivity in the range of 0.004 to 0.006 .OMEGA.-cm or a low resistivity N-type wafer having a 5-20 .mu.m thick N-type silicon epitaxial layer with a resistivity in a range of 0.004-0.006 .OMEGA.-cm. The selectively deposited P-type layer may have a resistivity of 0.001-0.003 .OMEGA.-cm and a thickness of 1.5-3.0 .mu.m. The P-type layer is grown in a gas phase epitaxial reactor by etching the N-type wafer at a first temperature and then depositing heavily-doped silicon at a second, lower temperature.