Abstract: To fabricate a semiconductor memory, one or more pairs of first structures are formed over a semiconductor substrate. Each first structure comprises (a) a plurality of floating gates of memory cells and (b) a first conductive line providing control gates for the memory cells. The control gates overlie the floating gates. Each pair of the first structures corresponds to a plurality of doped regions each of which provides a source/drain region to a memory cell having the floating and control gates in one or the structure and a source/drain region to a memory cell having floating and control gates in the other one of the structures. For each pair, a second conductive line is formed whose bottom surface extends between the two structures and physically contacts the corresponding first doped regions. In some embodiments, the first doped regions are separated by insulation trenches. The second conductive line may form a conductive plug at least partially filling the region between the two first structures.

Abstract: A floating gate (110) of a nonvolatile memory cell is formed in a trench (114) in a semiconductor substrate (220). A dielectric (128) covers the surface of the trench. The wordline (140) has a portion overlying the trench. The cell's floating gate transistor has a first source/drain region (226), a channel region (224), and a second source/drain region (130). The dielectric (128) is stronger against leakage near at least a portion of the first source/drain region (122) than near at least a portion of the channel region. The stronger portion (128.1) of the additional dielectric improves data retention without increasing the programming and erase times if the programming and erase operations do not rely on a current through the stronger portion. Additional dielectric (210) has a portion located below the top surface of the substrate between the trench and a top part of the second source/drain region (130). The second source/drain region has a part located below the additional dielectric and meeting the trench.

Abstract: Nonvolatile memory wordlines (160) are formed as sidewall spacers on sidewalls of row structures (280). Each row structure may contain floating and control gates (120, 140), or some other elements. Pedestals (340) are formed adjacent to the row structures before the conductive layer (160) for the wordlines is deposited. The pedestals are formed in the area of the contact openings (330.1) that will be etched in an overlying dielectric (310) to form contacts to the wordlines. The pedestals raise the top surface of the wordline layer near the contact openings, so the contact opening etch can be made shorter. The pedestals also increase the minimum thickness of the wordline layer near the contact openings, so the loss of the wordline layer during the etch of the contact openings becomes less critical, and the photolithographic tolerances required for patterning the contact openings can be relaxed. The pedestals can be dummy structures (they may have no electrical functionality).

Abstract: Nonvolatile memory wordlines (160) are formed as sidewall spacers on sidewalls of row structures (280). Each row structure may contain floating and control gates (120, 140), or some other elements. Pedestals (340) are formed adjacent to the row structures before the conductive layer (160) for the wordlines is deposited. The pedestals are formed in the area of the contact openings (330.1) that will be etched in an overlying dielectric (310) to form contacts to the wordlines. The pedestals raise the top surface of the wordline layer near the contact openings, so the contact opening etch can be made shorter. The pedestals also increase the minimum thickness of the wordline layer near the contact openings, so the loss of the wordline layer during the etch of the contact openings becomes less critical, and the photolithographic tolerances required for patterning the contact openings can be relaxed. The pedestals can be dummy structures (they may have no electrical functionality).

Abstract: In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. the cells are erased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.

Abstract: In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. the cells are erased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.

Abstract: To fabricate a semiconductor memory, one or more pairs of first structures are formed over a semiconductor substrate. Each first structure comprises (a) a plurality of floating gates of memory cells and (b) a first conductive line providing control gates for the memory cells. The control gates overlie the floating gates. Each pair of the first structures corresponds to a plurality of doped regions each of which provides a source/drain region to a memory cell having the floating and control gates in one or the structure and a source/drain region to a memory cell having floating and control gates in the other one of the structures. For each pair, a second conductive line is formed whose bottom surface extends between the two structures and physically contacts the corresponding first doped regions. In some embodiments, the first doped regions are separated by insulation trenches. The second conductive line may form a conductive plug at least partially filling the region between the two first structures.

Abstract: In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. The cells are crased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.

Abstract: A floating gate (110) of a nonvolatile memory cell is formed in a trench (114) in a semiconductor substrate (220). A dielectric (128) covers the surface of the trench. The wordline (140) has a portion overlying the trench. The cell's floating gate transistor has a first source/drain region (226), a channel region (224), and a second source/drain region (130). The dielectric (128) is stronger against leakage near at least a portion of the first source/drain region (122) than near at least a portion of the channel region. The stronger portion (128.1) of the additional dielectric improves data retention without increasing the programming and erase times if the programming and erase operations do not rely on a current through the stronger portion. Additional dielectric (210) has a portion located below the top surface of the substrate between the trench and a top part of the second source/drain region (130). The second source/drain region has a part located below the additional dielectric and meeting the trench.

Abstract: Aluminum oxide is deposited by atomic layer deposition to form a high-k dielectric for the interpoly dielectric layer of a non-volatile memory device. The increased capacitive coupling can allow a thicker oxide layer to be used between the floating gate and the control gate, resulting in improved reliability and longer lifetime of the memory cells fabricated according to this invention.

Abstract: In this invention a stacked gate flash memory cell is disclosed which has a lightly doped drain (LDD) on the drain side of the device and uses the source to both program using hot electron generation and erase the floating gate using Fowler-Nordheim tunneling. Disturb conditions are reduced by taking advantage of the LDD and the biasing of the cell that uses the source for both programming and erasure. The electric field of the drain is greatly reduced as a result of the LDD which reduces hot electron generation. The LDD also helps reduce bit line disturb conditions during programming. A transient bit line disturb condition in a non-selected cell is minimized by preconditioning the bit line to the non-selected cell to Vcc.

Abstract: In each row of a nonvolatile memory array, the select gates of all the memory cells are connected together and are used to select a row for memory access. The control gates of each row are also connected together, and the source regions of each row are connected together. Also, the control gates of plural rows are connected together, and the source regions of plural rows are connected together, but if the source regions of two rows are connected together, then their control gates are not connected together. If one of the two rows is being accessed but the other one of the two rows is not being accessed, their control gates are driven to different voltages, reducing the probability of a punch-through in the non-accessed row.

Abstract: In this invention a stacked gate flash memory cell is disclosed which has a lightly doped drain (LDD) on the drain side of the device and uses the source to both program using hot electron generation and erase the floating gate using Fowler-Nordheim-tunneling. Disturb conditions are reduced by taking advantage of the LDD and the biasing of the cell that uses the source for both programming and erasure. The electric field of the drain is greatly reduced as a result of the LDD which reduces hot electron generation. The LDD also helps reduce bit line disturb conditions during programming. A transient bit line disturb condition in a non-selected cell is minimized by preconditioning the bit line to the non-selected cell to Vcc.

Abstract: In each row of a nonvolatile memory array, the select gates of all the memory cells are connected together and are used to select a row for memory access. The control gates of each row are also connected together, and the source regions of each row are connected together. Also, the control gates of plural rows are connected together, and the source regions of plural rows are connected together, but if the source regions of two rows are connected together, then their control gates are not connected together. If one of the two rows is being accessed but the other one of the two rows is not being accessed, their control gates are driven to different voltages, reducing the probability of a punch-through in the non-accessed row.

Abstract: In a nonvolatile memory, a floating gate includes a portion of a conductive layer (150), and also includes conductive spacers (610). The spacers increase the capacitive coupling between the floating gate and the control gate (170).

Abstract: In a nonvolatile memory, a floating gate includes a portion of a conductive layer (150), and also includes conductive spacers (610). The spacers increase the capacitive coupling between the floating gate and the control gate (170).

Abstract: To fabricate a semiconductor memory, one or more pairs of first structures are formed over a semiconductor substrate. Each first structure comprises (a) a plurality of floating gates of memory cells and (b) a first conductive line providing control gates for the memory cells. The control gates overlie the floating gates. Each pair of the first structures corresponds to a plurality of doped regions each of which provides a source/drain region to a memory cell having the floating and control gates in one or the structure and a source/drain region to a memory cell having floating and control gates in the other one of the structures. For each pair, a second conductive line is formed whose bottom surface extends between the two structures and physically contacts the corresponding first doped regions. In some embodiments, the first doped regions are separated by insulation trenches. The second conductive line may form a conductive plug at least partially filling the region between the two first structures.

Abstract: To fabricate a semiconductor memory, one or more pairs of first structures are formed over a semiconductor substrate. Each first structure comprises (a) a plurality of floating gates of memory cells and (b) a first conductive line providing control gates for the memory cells. The control gates overlie the floating gates. Each pair of the first structures corresponds to a plurality of doped regions each of which provides a source/drain region to a memory cell having the floating and control gates in one or the structure and a source/drain region to a memory cell having floating and control gates in the other one of the structures. For each pair, a second conductive line is formed whose bottom surface extends between the two structures and physically contacts the corresponding first doped regions. In some embodiments, the first doped regions are separated by insulation trenches. The second conductive line may form a conductive plug at least partially filling the region between the two first structures.

Abstract: In each row of a nonvolatile memory array, the select gates of all the memory cells are connected together and are used to select a row for memory access. The control gates of each row are also connected together, and the source regions of each row are connected together. Also, the control gates of plural rows are connected together, and the source regions of plural rows are connected together, but if the source regions of two rows are connected together, then their control gates are not connected together. If one of the two rows is being accessed but the other one of the two rows is not being accessed, their control gates are driven to different voltages, reducing the probability of a punch-through in the non-accessed row.

Abstract: In each row of a nonvolatile memory array, the select gates of all the memory cells are connected together and are used to select a row for memory access. The control gates of each row are also connected together, and the source regions of each row are connected together. Also, the control gates of plural rows are connected together, and the source regions of plural rows are connected together, but if the source regions of two rows are connected together, then their control gates are not connected together. If one of the two rows is being accessed but the other one of the two rows is not being accessed, their control gates are driven to different voltages, reducing the probability of a punch-through in the non-accessed row.