| 摘要 |
<p>A multi-level non-volatile memory transistor (33) is formed in a semiconductor substrate (57). A conductive polysilicon control gate (51; 62) having opposed sidewalls is insulatively spaced (56) just above the substrate. Conductive polysilicon spacers (53, 55;91, 93) are separated from the opposed sidewalls by thin tunnel oxide (59; 74). Source and drain implants (61, 63; 101, 103) are beneath or slightly outboard of the spacers. Insulative material (104, 109) is placed over the structure with a hole (125) cut above the control gate for contact by a gate electrode (127) connected to, or part of, a conductive word line. Auxiliary low voltage transistors (23-26) which may be made at the same time as the formation of the memory transistor apply opposite phase clock pulses((~1, p2) to source and drain electrodes so that first one side of the memory transistor may be written to, or read, then t he other side.</p> |
