Abstract: The invention relates to a high density read only memory and fabrication method thereof through fabricating a plurality of spaced post transistors on a wafer by implanting and trench etching wherein each post transistor has four vertical surfaces with one of vertical surfaces as a short circuit junction between substrate and source and a read only memory (ROM) cell formed on each of the three remaining vertical surfaces. Therefore, the invention can fabricate three ROM cells in a single post transistor having a high density feature for storing three-bit data.

Abstract: The invention relates to a high density read only memory and fabrication method thereof through fabricating a plurality of spaced post transistors on a wafer by implanting and trench etching wherein each post transistor has four vertical surfaces with one of vertical surfaces as a short circuit junction between substrate and source and a read only memory (ROM) cell formed on each of the three remaining vertical surfaces. Therefore, the invention can fabricate three ROM cells in a single post transistor having a high density feature for storing. three-bit data.

Abstract: The invention relates to a high density read only memory and fabrication method thereof through fabricating a plurality of spaced post transistors on a wafer by implanting and trench etching wherein each post transistor has four vertical surfaces with one of vertical surfaces as a short circuit junction between substrate and source and a read only memory (ROM) cell formed on each of the three remaining vertical surfaces. Therefore, the invention can fabricate three ROM cells in a single post transistor having a high density feature for storing three-bit data.