Method of forming ONO-type sidewall with reduced bird's beak
    1.
    发明授权
    Method of forming ONO-type sidewall with reduced bird's beak 有权
    用鸟喙形成ONO型侧壁的方法

    公开(公告)号:US07910429B2

    公开(公告)日:2011-03-22

    申请号:US10821100

    申请日:2004-04-07

    IPC分类号: H01L21/336

    摘要: Conventional fabrication of sidewall oxide around an ONO-type memory cell stack usually produces Bird's Beak because prior to the fabrication, there is an exposed sidewall of the ONO-type memory cell stack that exposes side parts of a plurality of material layers respectively composed of different materials. Certain materials in the stack such as silicon nitrides are more difficult to oxidize than other materials in the stack such polysilicon. As a result oxidation does not proceed uniformly along the multi-layered height of the sidewall. The present disclosure shows how radical-based fabrication of sidewall dielectric can help to reduce the Bird's Beak formation. More specifically, it is indicated that short-lived oxidizing agents (e.g., atomic oxygen) are able to better oxidize difficult to oxidize materials such as silicon nitride and the it is indicated that the short-lived oxidizing agents alternatively or additionally do not diffuse as deeply through already oxidized layers of the sidewall such as silicon oxide layers. As a result, a more uniform sidewall dielectric can be fabricated with more uniform breakdown voltages along it height.

    摘要翻译: 通常在ONO型存储单元堆叠周围制造侧壁氧化物通常产生鸟喙,因为在制造之前,存在ONO型存储单元堆叠的暴露的侧壁,其暴露分别由不同的多个材料层组成的多个材料层的侧面部分 材料 堆叠中的某些材料如氮化硅比堆叠中的其它材料更难以氧化,这样的多晶硅。 结果,氧化不沿着侧壁的多层高度均匀地进行。 本公开显示了基于侧壁电介质的基于基础的制造有助于减少鸟喙形成。 更具体地,表明短寿命氧化剂(例如原子氧)能够更好地氧化难以氧化的材料如氮化硅,并且表明短寿命氧化剂交替地或另外不扩散为 深深地通过侧壁的已氧化层,例如氧化硅层。 结果,可以制造更均匀的侧壁电介质,沿其高度具有更均匀的击穿电压。