Method to increase coupling ratio of source to floating gate in split-gate flash
    11.
    发明申请
    Method to increase coupling ratio of source to floating gate in split-gate flash 有权
    提高分流栅闪光时源极与浮栅耦合比的方法

    公开(公告)号:US20050207264A1

    公开(公告)日:2005-09-22

    申请号:US11122726

    申请日:2005-05-05

    摘要: A split-gate flash memory cell having a three-dimensional source capable of three-dimensional coupling with the floating gate of the cell, as well as a method of forming the same are provided. This is accomplished by first forming an isolation trench, lining it with a conformal oxide, then filling with an isolation oxide and then etching the latter to form a three-dimensional coupling region in the upper portion of the trench. A floating gate is next formed by first filling the three-dimensional region of the trench with polysilicon and etching it. The control gate is formed over the floating gate with an intervening inter-poly oxide. The floating gate forms legs extending into the three-dimensional coupling region of the trench thereby providing a three-dimensional coupling with the source which also assumes a three-dimensional region. The leg or the side-wall of the floating gate forming the third dimension provides the extra area through which coupling between the source and the floating gate is increased. In this manner, a higher coupling ratio is achieved without an increase in the cell size while at the same time alleviating the punchthrough and junction break-down of source region by sharing gate voltage along the side-wall.

    摘要翻译: 提供具有能够与电池的浮动栅极三维耦合的三维源的分裂栅极闪存单元及其形成方法。 这是通过首先形成隔离沟槽,用共形氧化物衬里,然后用隔离氧化物填充,然后对其进行蚀刻,以在沟槽的上部形成三维耦合区域。 接下来通过用多晶硅填充沟槽的三维区域并对其进行蚀刻来形成浮栅。 控制栅极通过中间多晶硅氧化物形成在浮动栅上。 浮栅形成延伸到沟槽的三维耦合区域中的支腿,从而提供与源也呈三维区域的三维耦合。 形成第三维的浮动栅的腿或侧壁提供了增加源极和浮动栅极之间的耦合的额外区域。 以这种方式,在不增加电池尺寸的同时实现更高的耦合比,同时通过沿着侧壁共享栅极电压来减轻源极区域的穿通和结断流。

    Method to fabricate poly tip in split gate flash
    12.
    发明授权
    Method to fabricate poly tip in split gate flash 有权
    在分流闸闪光灯中制造多头尖端的方法

    公开(公告)号:US06635922B1

    公开(公告)日:2003-10-21

    申请号:US09654829

    申请日:2000-09-05

    IPC分类号: H01L29788

    摘要: A method is provided to form a sharp poly tip to improve the speed of a split-gate flash memory. The sharp poly tip is provided in place of the conventional gate bird's beak (GBB) because the latter requires the forming of thick poly-oxide which is more and more difficult in the miniaturized circuits of the ultra scale integrated technology. Furthermore, it is well known that GBB encroaches under the gate edge in a split-gate flash and degrades the programmability of submicron memory cells. The sharp poly tip of the invention is provided by forming a tapered floating gate through a high pressure etch such that the tip of the upper edge of the floating gate under the poly oxide is sharper and more robust, and, therefore, less susceptible to damage during the manufacture of the cell. The invention is also directed to a semiconductor device fabricated by the disclosed method.

    摘要翻译: 提供了一种形成尖锐的多晶硅尖端以提高分流栅闪存的速度的方法。 提供尖锐的多头尖端来代替常规的门鸟嘴(GBB),因为后者需要形成在超级集成技术的小型化电路中越来越困难的厚的多晶氧化物。 此外,众所周知,GBB在分割门闪存中的栅极边缘下侵入并降低亚微米存储器单元的可编程性。 通过高压蚀刻形成锥形浮栅,使得多晶氧化物下方的浮栅的上边缘的尖端更清晰,更坚固,因而不易受损,从而提供本发明的尖锐的多尖端 在电池的制造期间。 本发明还涉及通过所公开的方法制造的半导体器件。

    Method to fabricate split-gate with self-aligned source and self-aligned floating gate to control gate
    13.
    发明授权
    Method to fabricate split-gate with self-aligned source and self-aligned floating gate to control gate 有权
    用自对准源和自对准浮栅制作分闸的控制门的方法

    公开(公告)号:US06228695B1

    公开(公告)日:2001-05-08

    申请号:US09320759

    申请日:1999-05-27

    IPC分类号: H01L218238

    摘要: A split-gate flash memory cell having self-aligned source and floating gate self-aligned to control gate is disclosed as well as a method of forming the same. This is accomplished by depositing over a gate oxide layer on a silicon substrate a poly-1 layer to form a vertical control gate followed by depositing a poly-2 layer to form a spacer floating gate adjacent to the control gate with an intervening intergate oxide layer. The source is self-aligned and the floating gate is also formed to be self-aligned to the control gate, thus making it possible to reduce the cell size. The resulting self-aligned source alleviates punch-through from source to control gate while the self-aligned floating gate with respect to the control gate provides improved programmability. The method also replaces the conventional poly oxidation process thereby yielding improved sharp peak of floating gate for improved erasing and writing of the split-gate flash memory cell.

    摘要翻译: 公开了一种具有自对准源和对准控制栅极的浮置栅极的分裂栅极闪存单元及其形成方法。 这通过在硅衬底上的栅极氧化物层上沉积多晶层来实现,以形成垂直控制栅极,随后沉积多晶硅层以形成与控制栅极相邻的间隔物浮动栅极,其中间隔栅极氧化层 。 源极是自对准的,并且浮栅也形成为与对栅极自对准,从而可以减小电池的尺寸。 所产生的自对准源减轻了从源极到控制栅极的穿通,而相对于控制栅极的自对准浮动栅极提供了改进的可编程性。 该方法也取代了传统的多晶氧化工艺,从而产生改善的浮栅的尖峰,以改善分离栅闪存单元的擦除和写入。

    Method to increase coupling ratio of source to floating gate in
split-gate flash

    公开(公告)号:US6159801A

    公开(公告)日:2000-12-12

    申请号:US298932

    申请日:1999-04-26

    摘要: A split-gate flash memory cell having a three-dimensional source capable of three-dimensional coupling with the floating gate of the cell, as well as a method of forming the same are provided. This is accomplished by first forming an isolation trench, lining it with a conformal oxide, then filling with an isolation oxide and then etching the latter to form a three-dimensional coupling region in the upper portion of the trench. A floating gate is next formed by first filling the three-dimensional region of the trench with polysilicon and etching it. The control gate is formed over the floating gate with an intervening inter-poly oxide. The floating gate forms legs extending into the three-dimensional coupling region of the trench thereby providing a three-dimensional coupling with the source which also assumes a three-dimensional region. The leg or the side-wall of the floating gate forming the third dimension provides the extra area through which coupling between the source and the floating gate is increased. In this manner, a higher coupling ratio is achieved without an increase in the cell size while at the same time alleviating the punchthrough and junction break-down of source region by sharing gate voltage along the side-wall.

    Source side injection programming and tip erasing P-channel split gate flash memory cell
    15.
    发明授权
    Source side injection programming and tip erasing P-channel split gate flash memory cell 有权
    源端注入编程和引脚擦除P沟道分离栅极闪存单元

    公开(公告)号:US06573555B1

    公开(公告)日:2003-06-03

    申请号:US09587464

    申请日:2000-06-05

    IPC分类号: H01L29788

    CPC分类号: H01L29/42324 H01L21/28273

    摘要: A split gate P-channel flash memory cell and method of forming a split gate P-channel flash memory cell which avoids of high erasing voltage, reverse tunneling during programming, drain disturb and over erase problems, and permits shrinking the cell dimensions. The control gate has a concave top surface which intersects with the sidewalls to form a sharp edge. The cell is programmed by charging the floating gate with electrons by means of hot electron injection from the channel into the floating gate. The cell is erased by discharging the excess electrons from the floating gate into the control gate using Fowler-Nordheim tunneling. The sharp edge at the intersection of the concave top surface and the sidewalls of the floating gate produces a high electric field between the control gate and the floating gate to accomplish the Fowler-Nordheim tunneling with only moderate voltage differences between the floating gate and control gate. The P-channel flash memory cell has a higher impact ionization rage for creating hot electrons so that the distance between the source and drain junctions and the length of the floating gate can be kept small thereby permitting the dimensions of the flash memory cell to be shrunk.

    摘要翻译: 分裂门P沟道快闪存储单元以及形成分离栅极P沟道闪存单元的方法,其避免高擦除电压,编程期间的反向隧穿,漏极干扰和过度擦除问题,并且允许缩小单元尺寸。 控制门具有与侧壁相交以形成锋利边缘的凹顶表面。 通过从通道进入浮动栅极的热电子注入,用电子对浮动栅极充电来对单元进行编程。 使用Fowler-Nordheim隧道将多余的电子从浮动栅极放电到控制栅中来消除电池。 在凹顶表面和浮动栅极的相交处的尖锐边缘在控制栅极和浮动栅极之间产生高电场,以在浮动栅极和控制栅极之间仅具有适度的电压差来实现Fowler-Nordheim隧道 。 P沟道闪速存储单元对于产生热电子具有较高的冲击电离强度,使得源极和漏极结之间的距离和浮置栅极的长度可以保持较小,从而允许闪存单元的尺寸缩小 。

    Split-gate flash cell
    16.
    发明授权
    Split-gate flash cell 有权
    分离式闪存单元

    公开(公告)号:US06538277B2

    公开(公告)日:2003-03-25

    申请号:US09920601

    申请日:2001-08-02

    IPC分类号: H01L29788

    摘要: A novel method of forming a first polysilicon gate tip (poly-tip) for enhanced F-N tunneling in split-gate flash memory cells is disclosed. The poly-tip is formed in the absence of using a thick polysilicon layer as the floating gate. This is made possible by forming an oxide layer over the poly-gate and oxidizing the sidewalls of the polygate. Because the starting thickness of polysilicon of the floating gate is relatively thin, the resulting gate beak, or poly-tip, is also necessarily thin and sharp. This method, therefore, circumvents the problem of oxide thinning encountered in scaling down devices of the ultra large scale integration technology and the fast programmability and erasure performance of EEPROMs is improved.

    摘要翻译: 公开了一种形成分裂栅闪存单元中用于增强的F-N隧穿的第一多晶硅栅尖(多尖端)的新方法。 在不使用厚多晶硅层作为浮动栅极的情况下形成多尖端。 这可以通过在多晶硅上形成氧化层并氧化多晶硅的侧壁来实现。 由于浮栅的多晶硅的起始厚度相对较薄,所以形成的栅极尖或多尖端也必然是薄且尖锐的。 因此,该方法避免了超大规模集成技术的缩小设备中遇到的氧化物薄化问题,提高了EEPROM的快速可编程性和擦除性能。

    Structure with protruding source in split-gate flash

    公开(公告)号:US06534821B2

    公开(公告)日:2003-03-18

    申请号:US09927071

    申请日:2001-08-10

    IPC分类号: H01L29788

    CPC分类号: H01L27/11521 H01L27/115

    摘要: A method is disclosed for forming a split-gate flash memory cell having a protruding source in place of the conventional flat source. The vertically protruding source structure has a top portion and a bottom portion. The bottom portion is polysilicon while the top portion is poly-oxide. The vertical wall of the protruding structure over the source is used to form vertical floating gate and spacer control gate with an intervening inter-gate oxide. Because the coupling between the source and the floating gate is now provided through the vertical wall, the coupling area is much larger than with conventional flat source. Furthermore, there is no longer the problem of voltage punch-through between the source and the drain. The vertical floating gate is also made thin so that the resulting thin and sharp poly-tip enhances further the erasing and programming speed of the flash memory cell. The vertical orientation of the source structure and the floating gate and the self-alignment of the spacer control gate to the floating gate together makes it possible to reduce the memory cell substantially.

    Method of forming sharp beak of poly by nitrogen implant to improve erase speed for split-gate flash
    18.
    发明授权
    Method of forming sharp beak of poly by nitrogen implant to improve erase speed for split-gate flash 有权
    通过氮注入形成聚合尖锐尖嘴的方法,以提高分流栅闪光的擦除速度

    公开(公告)号:US06188103B1

    公开(公告)日:2001-02-13

    申请号:US09196600

    申请日:1998-11-20

    IPC分类号: H01L29788

    CPC分类号: H01L29/66825 H01L29/42324

    摘要: A method is provided for forming a short and sharp gate bird's beak in order to increase the erase speed of a split-gate flash memory cell. This is accomplished by implanting nitrogen ions in the first polysilicon layer of the cell and removing them from the area where the floating gate is to be formed. Then, when the polysilicon layer is oxidized to form polyoxide, the floating gate region without the nitrogen ions oxidizes faster than the surrounding area still having the nitrogen ions. Consequently, the bird's beak that is formed at the edges of the polyoxide assumes a sharper shape with smaller size than that is found in prior art. This results in an increase in the erase speed of the memory cell.

    摘要翻译: 提供了一种用于形成短而尖锐的门鸟喙的方法,以便增加分闸式闪存单元的擦除速度。 这是通过在电池的第一多晶硅层中注入氮离子并将其从要形成浮栅的区域中去除来实现的。 然后,当多晶硅层被氧化形成聚氧化物时,没有氮离子的浮栅区域比仍然具有氮离子的周围区域更快地氧化。 因此,形成在多氧化物边缘的鸟嘴形状比现有技术中发现的具有更小的形状。 这导致存储单元的擦除速度的增加。

    Method of fabricating buried source to shrink cell dimension and
increase coupling ratio in split-gate flash
    19.
    发明授权
    Method of fabricating buried source to shrink cell dimension and increase coupling ratio in split-gate flash 失效
    埋入源的方法,以收缩电池尺寸并增加分流栅闪电中的耦合比

    公开(公告)号:US6017795A

    公开(公告)日:2000-01-25

    申请号:US72996

    申请日:1998-05-06

    IPC分类号: H01L21/8247 H01L27/115

    CPC分类号: H01L27/11521 H01L27/115

    摘要: A method is provided for forming a split-gate flash memory cell having reduced size, partially buried source line, increased source coupling ratio, improved programmability, and overall enhanced performance. A split-gate cell is also provided with reduced size and improved performance. The source line is formed in a trench in the substrate over the source region. The trench walls provide increased source coupling and the absence of gate bird's beak with the trench together shrink the cell size. Programmability is also enhanced through more favorable hot electron injection though intergate oxide between the floating gate and the control gate.

    摘要翻译: 提供了一种用于形成具有减小的尺寸,部分埋入的源极线,增加的源耦合比,改进的可编程性和整体增强性能的分裂栅极快闪存储器单元的方法。 分裂门电池还具有减小的尺寸和改进的性能。 源极线形成在源极区域上的衬底中的沟槽中。 沟槽壁提供增加的源耦合,并且没有门鸟的喙与沟槽一起收缩细胞尺寸。 通过浮动栅极和控制栅极之间的隔间氧化物,通过更有利的热电子注入也可以提高可编程性。

    Split-gate flash cell for virtual ground architecture

    公开(公告)号:US06249454B1

    公开(公告)日:2001-06-19

    申请号:US09396519

    申请日:1999-09-15

    IPC分类号: G11C1604

    摘要: In this invention bit lines are ion implanted into a semiconductor substrate in columns beside floating gates of an array of flash memory cells. A control gate overlays each row floating gates and operates as a word lines for the rows of flash memory cells. Each bit line serves a dual purpose of providing a drain for one cell and a source for the adjacent cell. The flash memory cells are programmed, erased and read depending upon the voltages applied to the buried bit lines and the word line structured as a control gate that extends the length of each row. By implanting the bit lines into the semiconductor substrate the flash memory cell can be made smaller improving the density of the flash memory.