Laser stress measurement apparatus and method
    5.
    发明授权
    Laser stress measurement apparatus and method 失效
    激光应力测量装置及方法

    公开(公告)号:US4991964A

    公开(公告)日:1991-02-12

    申请号:US237603

    申请日:1988-08-26

    IPC分类号: G01B11/16

    CPC分类号: G01B11/16

    摘要: In semiconductor processing, it is desirable to protectively cover the wafer (40) prior to sawing the wafer (40) into individual chips. The compressive nitride protective cover tends to bow the normally flat surface of the wafer (40). If the compressive stress is too great, the wafer (40) and the circuits thereon may be damaged. The laser stress measurement apparatus (10) provides a method for checking the wafer (40) for excess stress without destroying the wafer (40). A light source (12) emits a beam of light onto a reflector (22) which reflects the light onto wafer (40). The light is deflected by wafer (40) back to the reflector (22) and thence to a light detector (52). The light detector (52) is positioned to receive the light in an exact center such that subsequent readings may be taken to determine a change in deflection. The change in deflection is then used in a formula to determine the compressive stress on wafer (40).

    摘要翻译: 在半导体处理中,期望在将晶片(40)锯切成单个芯片之前保护性地覆盖晶片(40)。 压缩氮化物保护罩倾向于使晶片(40)的正常平坦表面弯曲。 如果压缩应力太大,则晶片(40)及其上的电路可能被损坏。 激光应力测量装置(10)提供了用于在不破坏晶片(40)的情况下检查晶片(40)的过度应力的方法。 光源(12)将光束发射到将光反射到晶片(40)上的反射器(22)上。 光被晶片(40)偏转回到反射器(22),从而被光检测器(52)偏转。 光检测器(52)被定位成在准确的中心接收光,使得可以采用随后的读数来确定偏转的变化。 然后在公式中使用偏转的变化来确定晶片(40)上的压缩应力。