Texas Instruments Corporation

Bert R Riemenschneider

Allan T Mitchell

Howard L Tigelaar

David K Liu

Clarence W Teng

James L Paterson

Kueing-Long Chen

Richard A Chapman

David D Wilmoth

Andrew T Appel

Howard L Tigilaar

This antifuse includes: a sublithographic conductive pattern (18); an antifuse material (24) overlying said sublithographic conductive pattern (18); and a conductive layer (26) overlying the antifuse material (24) to form a reduced area antifuse (10). Other devices, systems and methods are also disclosed.

Sublithographic antifuse

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.

Process for thickening selective gate oxide regions

A described embodiment of the present invention includes an anti-fuse comprising: a first conductive layer having a horizontal major surface and having a substantially vertical sidewall; a thick insulating layer formed on the horizontal major surface of the first conductive layer; a dielectric layer formed on the vertical sidewall; and a second conductive layer formed on the dielectric layer. In an additional embodiment, the first and/or second conductive layers comprise polycrystalline silicon and a conductive material selected from the group of titanium, tungsten, molybdenum, platinum, titanium silicide, tungsten silicide, molybdenum silicide, platinum silicide, titanium nitride and combinations thereof.

Sidewall anti-fuse structure and method for making

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.

Trench capacitor DRAM cell and method of manufacture

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.

Non-volatile semiconductor memory

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.

High density EPROM fabricaiton method having sidewall floating gates

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.

Fabricating a single level merged EEPROM cell having an ONO memory stack

Trench capacitor DRAM cell with diffused bit lines adjacent to a trench

A non-volatile memory is provided which provides a floating gate (42) disposed over control gate (38) in order to increase the coupling therebetween. The degree of coupling may be varied by adjusting the area of the floating gate formed over the control gate relative to the area of the floating gate over the substrate.

Non-volatile memory with improved coupling between gates

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).

Method of making high density EEPROM

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.

Erasable programmable memory including buried diffusion source/drain

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).

EEPROM including programming electrode extending through the control

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).

X-cell EEPROM array

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.

Method for increasing source/drain to channel stop breakdown and

The present invention provides a structure and method for fabricating that structure which provides increased capacitance over the prior art while occupying a minimum of surface area of the integrated circuit. The present invention accomplishes this by interleaving multiple capacitor plates to provide increased capacitance while occupying the same surface area as a prior art capacitor providing a fraction of the capacitance provided by the present invention. The present invention is fabricated by providing a capacitor stack which includes interleaved plates of material which may be selectively etched and which is separated by appropriate dielectric material. One portion of the stack is masked while one set of the interleave plates is etched. The etched portion of the interleave plates is filled by a suitable dielectric and a contact is made to the remaining plates. A different portion of the stack is then exposed to an etch which etches the other set of interleave plates. The area etched away is then filled with a suitable dielectric and a contact is made to the unetched interleaved plates. Thus a fully interleaved capacitor is provided using relatively simple fabrication techniques while still providing increased capacitance.

Growing community of inventors

Murphy, TX, United States of America

Bert R Riemenschneider