摘要:
An EPROM memory having sidewall floating gates (30) is disclosed. Sidewall floating gates (30) are formed on sidewalls (28) of field insulators (24). Spaced apart bit lines (22), which serve as memory cell sources and drains, are formed. The field insulators (24) overlie the bit lines (22), and sidewall floating gates are formed on the sidewalls (28) of the field insulators (24). In one embodiment, a second set of bit lines (36) is formed between the sidewall floating gates (30), and each memory cell contains one sidewall floating gate (30). In another embodiment, each memory cell contains two sidewall floating gate (30), and the memory cell may be programmed to store from two to four distinct information states.
摘要:
An EEPROM cell and array of cells is disclosed having buried diffusion source/drain lines and buried diffusion erase lines. The cells further include coupling between the floating gate and control gate above the source/drain diffusion. The disclosed cell allows high packing density and operation at low voltages.
摘要:
An electrically erasable, programmable read only memory (EEPROM) having an erase window directly overlying both a control gate layer (24) and a column line (12) is disclosed. Column lines (12) are implanted into a semiconductor substrate (16) and covered with a first insulating layer (18). A floating gate layer (20) overlies the first insulating layer (18) and is covered with a second insulating layer (22). The control gate layer (24) overlies the second insulating layer (22) and is covered by a third insulating layer (26). A passage (28) extends through the third insulating layer (26), control gate layer (24) and second insulating layer (22) and contains a sidewall insulator (30) on walls thereof. A tunnel oxide (32) resides within the passage (28) and is contacted by a programming electrode layer (34) which additionally overlies the third insulating layer (26) and fills the passage (28).
摘要:
One embodiment of the present invention is a method of simultaneously forming high-voltage (12) and low-voltage (10) devices on a single substrate (14), the method comprising: forming a thin oxide layer (18) on the substrate, the thin oxide layer having a desired thickness for a gate oxide for the low-voltage device; selectively forming a gate structure (30) for the high-voltage device, the thin oxide is situated between the gate structure and the substrate; and selectively thickening the thin oxide under the gate structure while keeping the thin oxide layer utilized for the low-voltage device at the desired thickness.
摘要:
A plurality of trenches (26, 28) of a DRAM cell array formed in a (P-) epitaxial layer (11) and a silicon substrate (12), and storage layers (38, 40) are grown on the sidewalls (34, 36) and bottom (not shown) of the trenches (26, 28). Highly doped polysilicon capacitor electrodes (42, 44) are formed in the trenches (26, 28). Sidewall oxide filaments (50, 54) and in situ doped sidewall conductive filaments (66, 68) are formed and thermal cycles are used to diffuse dopant from sidewall conductive filaments (66, 68) into upper sidewall portions (62, 64) to form diffused source regions (70, 72) of pass gate transistors (90) for each cell.
摘要:
A small-area single-transistor EEPROM memory cell includes buried bit lines (44,46) extending through the array and connecting together many memory cells. Formed above a channel area (25) and between the bit lines (44,46) are oxide-nitride-oxide layers (50,52,54) for providing isolation between overlying polysilicon word lines (56, 66) and the underlying conduction channel (25). The nitride layer (52) provides the charge retention mechanism for programming the memory cell. The word lines (56, 66) provide electrical contact to a number of memory cells in the row. Electrical contact is made to the word lines (56, 66) by metal contacts (68, 70), and to the bit lines (44,46) by metal contacts (72, 74) at the array periphery, thereby avoiding metal contacts to every memory cell of the array. A EEPROM memory cell of 4-5.2 microns can be fabricated.
摘要:
An electrically erasable, programmable read only memory (EEPROM) having an erase window directly overlying both a control gate layer (24) and a column line (12) is disclosed. Column lines (12) are implanted into a semiconductor substrate (16) and covered with a first insulating layer (18). A floating gate layer (20) overlies the first insulating layer (18) and is covered with a second insulating layer (22). The control gate layer (24) overlies the control insulating layer (22) and is covered by a third insulating layer (26). A passage (28) extends through the third insulating layer (26), control gate layer (24) and second insulating layer (22) and contains a sidewall insulator (30) on walls thereof. A tunnel oxide (32) resides within the passage (28) and is contacted by a programming electrode layer (34) which additionally overlies the third insulating layer (26) and fills the passage (28).