Method for fabricating a multilayer epitaxial structure
    2.
    发明授权
    Method for fabricating a multilayer epitaxial structure 失效
    制造多层外延结构的方法

    公开(公告)号:US5432121A

    公开(公告)日:1995-07-11

    申请号:US242877

    申请日:1994-05-16

    IPC分类号: H01L21/22 H01L21/20

    CPC分类号: H01L21/2205 Y10S148/041

    摘要: An all epitaxial process performed entirely in a CVD reactor is employed to grow epitaxial layers with accurately controlled successively low and high dopant concentrations over a heavily doped substrate, eliminating the need for a separate diffusion, even for high purity concentrations. After purging the reactor system, the heavily doped silicon substrate is "capped" by growing two successive very thin silicon sublayers of the same conductivity type. The reactor chamber is subjected to a hydrogen purge to deplete any contaminents after each sublayer is formed. The cap sublayers form a narrow, abrupt intrinsic transition region with the substrate and become an active part of the device structure. A lightly doped epitaxial layer is grown over the "capped" substrate so that a depletion region can be formed in the device under suitable reverse bias. A heavily doped epitaxial layer is then grown over the lightly doped epitaxial layer. The heavily doped epitaxial layer forms a contact layer and has a polarity opposite to that of the substrate.

    摘要翻译: 采用在CVD反应器中完全执行的全部外延工艺来在重掺杂衬底上生长具有精确控制的连续低和高掺杂剂浓度的外延层,从而消除了对于高纯度浓度的单独扩散的需要。 在清洗反应器系统之后,通过生长相同导电类型的两个连续的非常薄的硅子层,重掺杂硅衬底被“封盖”。 在形成每个子层之后,对反应器室进行氢气净化以消除任何污染物。 帽子层与衬底形成窄的,突然的本征过渡区,并成为器件结构的有效部分。 在“封盖”衬底上生长轻掺杂的外延层,使得可以在合适的反向偏压下在器件中形成耗尽区。 然后在轻掺杂的外延层上生长重掺杂的外延层。 重掺杂的外延层形成接触层,并具有与衬底相反的极性。

    Low-voltage punch-through bi-directional transient-voltage suppression devices
    3.
    发明授权
    Low-voltage punch-through bi-directional transient-voltage suppression devices 有权
    低压穿通双向瞬态电压抑制装置

    公开(公告)号:US06489660B1

    公开(公告)日:2002-12-03

    申请号:US09862664

    申请日:2001-05-22

    IPC分类号: H01L2900

    CPC分类号: H01L29/66121 H01L29/8618

    摘要: A bi-directional transient voltage suppression device with symmetric current-voltage characteristics has a lower semiconductor layer of first conductivity type, an upper semiconductor layer of first conductivity type, and a middle semiconductor layer adjacent to and disposed between the lower and upper layers having a second opposite conductivity type, such that upper and lower p-n junctions are formed. The middle layer has a net doping concentration that is highest at a midpoint between the junctions. Furthermore, the doping profile along a line normal to the lower, middle and upper layers is such that, within the middle layer the doping profile on one side of a centerplane of the middle layer mirrors the doping profile on an opposite side. In addition, an integral of the net doping concentration of the middle layer taken over the distance between the junctions is such that breakdown, when it occurs, is punch through breakdown, rather than avalanche breakdown.

    摘要翻译: 具有对称电流 - 电压特性的双向瞬时电压抑制装置具有第一导电类型的下半导体层,第一导电类型的上半导体层和与下层和上层之间相邻并且设置在下层和上层之间的中间半导体层, 第二相反导电类型,使得形成上部和下部pn结。 中间层具有在接合点之间的中点处最高的净掺杂浓度。 此外,沿着垂直于下层,中层和上层的线的掺杂分布使得在中间层内,中间层的中心平面的一侧上的掺杂分布反映了相对侧上的掺杂分布。 此外,中间层的净掺杂浓度在接合点之间的距离的积分是这样的,当发生故障时,击穿是冲击破坏,而不是雪崩击穿。

    Method for fabricating a multilayer epitaxial structure
    4.
    发明授权
    Method for fabricating a multilayer epitaxial structure 失效
    制造多层外延结构的方法

    公开(公告)号:US5324685A

    公开(公告)日:1994-06-28

    申请号:US15384

    申请日:1993-02-09

    IPC分类号: H01L21/22 H01L21/203

    CPC分类号: H01L21/2205 Y10S438/902

    摘要: An all epitaxial process performed entirely in a CVD reactor is employed to grow heavily doped layer on lightly doped layer on a heavily doped substrate, eliminating the need for separate diffusion, even for high impurity concentrations. The process starts with a heavily doped silicon substrate of carrier concentration typically greater than 1.times.10.sup.19 per cm.sup.3. To minimize outdiffusion, the substrate is "capped" by growing very thin and heavily doped silicon layers which are depleted by hydrogen purges. A first epitaxial layer is grown over the "capped" substrate. This layer is relatively lightly doped, having a resistivity of more than 200 ohm.cm. A second epitaxial layer is then grown over the first epitaxial layer. The second epitaxial layer has a polarity opposite to that of the substrate and is heavily doped to a resistivity of less than 0.005 ohm cm.

    摘要翻译: 采用在CVD反应器中完全执行的全部外延工艺来在重掺杂衬底上的轻掺杂层上生长重掺杂层,即使对于高杂质浓度也无需分开扩散。 该过程从载流子浓度通常大于1×1019 / cm3的重掺杂硅衬底开始。 为了最小化扩散,通过生长非常薄且重掺杂的硅层,衬底被“封盖”,其被氢清除耗尽。 在“封盖”基板上生长第一外延层。 该层相对轻掺杂,电阻率大于200欧姆·厘米。 然后在第一外延层上生长第二外延层。 第二外延层具有与衬底相反的极性,并且被重掺杂到小于0.005欧姆厘米的电阻率。

    Semiconductor chips having a mesa structure provided by sawing
    5.
    发明授权
    Semiconductor chips having a mesa structure provided by sawing 失效
    具有通过锯切提供的台面结构的半导体芯片

    公开(公告)号:US5882986A

    公开(公告)日:1999-03-16

    申请号:US50106

    申请日:1998-03-30

    CPC分类号: H01L21/3043

    摘要: Starting with a semiconductor wafer of known type including an internal, planar p-n junction parallel to major surfaces of the wafer, one of the wafer surfaces is covered with a masking layer of silicon nitride. A plurality of intersecting grooves are then sawed through the masking layer for forming a plurality of mesas having sloped walls with each mesa including a portion of the planar p-n junction having edges which intersect and are exposed by the mesa walls. The groove walls and exposed junction edges are glass encapsulated in a process including heating the wafer. The masking layers are then removed in a selective etching process not requiring a patterned etchant mask, and the now exposed silicon surfaces at the top of the mesas, as well as the opposite surface of the wafer, are metal plated. The wafer is then diced along planes through the grooves for providing individual chips each having a glass passivated mesa thereon.

    摘要翻译: 从已知类型的半导体晶片开始,包括平行于晶片的主表面的内部平面p-n结,其中一个晶片表面被氮化硅掩蔽层覆盖。 然后通过掩模层锯切多个相交槽,以形成具有倾斜壁的多个台面,每个台面包括平面p-n结的一部分,其边缘与台面壁相交并暴露。 沟槽壁和暴露的接合边缘是玻璃封装在包括加热晶片的过程中。 然后在不需要图案化蚀刻剂掩模的选择性蚀刻工艺中去除掩模层,并且在台面顶部的现在暴露的硅表面以及晶片的相对表面是金属镀覆的。 然后将晶片沿着平面通过沟槽切割,以提供各自具有玻璃钝化台面的单个芯片。

    Low-voltage punch-through bi-directional transient-voltage suppression devices and methods of making the same
    6.
    发明授权
    Low-voltage punch-through bi-directional transient-voltage suppression devices and methods of making the same 有权
    低压穿通双向瞬态电压抑制装置及其制造方法

    公开(公告)号:US06602769B2

    公开(公告)日:2003-08-05

    申请号:US10264950

    申请日:2002-10-04

    IPC分类号: H02L2122

    CPC分类号: H01L29/66121 H01L29/8618

    摘要: A bi-directional transient voltage suppression device with symmetric current-voltage characteristics has a lower semiconductor layer of first conductivity type, an upper semiconductor layer of first conductivity type, and a middle semiconductor layer adjacent to and disposed between the lower and upper layers having a second opposite conductivity type, such that upper and lower p−n junctions are formed. The middle layer has a net doping concentration that is highest at a midpoint between the junctions. Furthermore, the doping profile along a line normal to the lower, middle and upper layers is such that, within the middle layer the doping profile on one side of a centerplane of the middle layer mirrors the doping profile on an opposite side. In addition, an integral of the net doping concentration of the middle layer taken over the distance between the junctions is such that breakdown, when it occurs, is punch through breakdown, rather than avalanche breakdown.

    摘要翻译: 具有对称电流 - 电压特性的双向瞬时电压抑制装置具有第一导电类型的下半导体层,第一导电类型的上半导体层和与下层和上层之间相邻并且设置在下层和上层之间的中间半导体层, 第二相反导电类型,使得形成上部和下部pn结。 中间层具有在接合点之间的中点处最高的净掺杂浓度。 此外,沿着垂直于下层,中层和上层的线的掺杂分布使得在中间层内,中间层的中心平面的一侧上的掺杂分布反映了相对侧上的掺杂分布。 此外,中间层的净掺杂浓度在接合点之间的距离的积分是这样的,当发生故障时,击穿是冲击破坏,而不是雪崩击穿。

    Low cost method of fabricating epitaxial semiconductor devices
    7.
    发明授权
    Low cost method of fabricating epitaxial semiconductor devices 失效
    制造外延半导体器件的低成本方法

    公开(公告)号:US5360509A

    公开(公告)日:1994-11-01

    申请号:US21130

    申请日:1993-03-08

    摘要: Significant reductions in the cost of fabrication of epitaxial semiconductor devices without sacrifice of functional characteristics is achieved by eliminating the conventional but costly polishing procedure, instead subjecting the substrate to grinding, cleaning and etching processes in which the grinding removes material from the surface to a depth of at least 65 microns and the etching further removes material to a depth of about 6-10 microns, the grinding preferably being carried out in two steps, the first being a coarse step and the second being a fine step, with the rotated grinding elements dwelling at their respective last grinding positions for a short period of time. The result is the equivalent of the prior art polishing procedure which took considerably longer to carry out and which therefore was much more costly. Complementing this grinding procedure is an improved and cost effective epitaxial process utilizing a unique two-step hydrochloric gas high temperature etch and a faster growth rate process with shorter cycle steps. In addition, oxygen control and "gettering" capabilities result in a total process improving the economics of formation of epitaxial semiconductor devices.

    摘要翻译: 通过消除常规但昂贵的抛光方法,可以显着降低外延半导体器件的制造成本,而不牺牲功能特性,而不是对基板进行研磨,清洗和蚀刻工艺,其中研磨将材料从表面移除到深度 至少65微米,并且蚀刻进一步将材料去除至约6-10微米的深度,研磨优选以两个步骤进行,第一步是粗步骤,第二步是精细步骤,旋转的研磨元件 住在他们各自的最后研磨位置很短的时间。 结果相当于现有技术的抛光程序,其花费相当长的时间来执行,因此成本更高。 补充该研磨程序是利用独特的两步盐酸气体高温蚀刻和具有较短循环步骤的更快生长速率工艺的改进且成本有效的外延工艺。 此外,氧气控制和“吸气”能力导致整个工艺改善外延半导体器件形成的经济性。