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 electrically, programmable read-only memory cell is formed at a face (10) of a semiconductor layer (12). This cell comprises a doped drain region (36) and a doped source region (38) that are spaced from each other by a gate region (40). An ONO memory stack (28) is formed to extend over a portion of the gate region (40) that adjoins the drain region (36). The memory stack (28) is substantially spaced from the source region (38). A select gate insulator layer (30) is formed over the remainder of the gate region (40), and is preferably of the same thickness as the memory stack (28). A suitable gate conductor (32) is then deposited over insulator layers (26, 30). By being substantially spaced from source region (38), the memory stack (28) of the invention avoids the formation of ONO hole traps.
摘要:
An X-cell EEPROM array includes a plurality of common source regions (50) that each border on four gate regions (46), both formed at a face of a semiconductor substrate (10). Each gate region (46) further adjoins a common drain region (52). Each drain region (52) is a common drain for two EEPROM select and memory transistors. A common erase region (54) is implanted into the semiconductor layer (10) in a position remote from the source regions (50) and the drain regions (52). Four floating gate electrodes (40) extend over tunnel windows (22) that are formed on the semiconductor layer (10) in positions adjacent a single erase region (54). An integral contact (64) is made through multilevel oxide (56, 58) from a metal erase line (70) to each erase region (54).
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:
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 method of forming semiconductor devices wherein a gap is formed beneath the field oxide between the channel stop implant and source/drain regions in the moat or active element region to prevent or minimize encroachment of channel stop impurity toward the source/drain regions to form spurious pn junctions and/or reduce the active element region.
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).
摘要:
An analog floating-gate electrode in an integrated circuit, and method of fabricating the same, in which trapped charge can be stored for long durations. The analog floating-gate electrode is formed in a polycrystalline silicon gate level, and includes n-type and p-type doped portions serving as gate electrodes of n-channel and p-channel MOS transistors, respectively; a plate of a metal-to-poly storage capacitor; and a plate of poly-to-active tunneling capacitors. Silicide-block silicon dioxide blocks the formation of silicide cladding on the electrode, while other polysilicon structures in the integrated circuit are silicide-clad. An opening at the surface of the analog floating-gate electrode, at the location at which n-type and p-type doped portions of the floating gate electrode abut, allow formation of silicide at that location, shorting the p-n junction.