公开(公告)号：US3924113A

公开(公告)日：1975-12-02

申请号：US36838473

申请日：1973-06-08

Applicant: IBM

Inventor： GILL CHARLES D ,  RYAN PHILIP M

IPC: H01J37/305 ,  G06F17/15 ,  G06F17/17 ,  G06F17/18 ,  H01J37/304 ,  H01L21/00 ,  H01L21/027 ,  G06F15/34 ,  H01J37/28

CPC classification number: H01J37/3045 ,  H01L21/00

Abstract: In semiconductor manufacture, very accurate patterns must be formed in the photoresist on the surface of the semiconductor material. Chips are formed on a semiconductor wafer utilizing a beam of charged particles to expose the photoresist material on the surface of the semiconductor. If the plurality of chips, is to have the same characteristics and pattern, it is necessary that the electrons or beam of charged particles be moved such that any point within the field to which the beam is applied is always reached by the same history. This requires that patterns produced by an electron beam be properly registered with respect to previously generated patterns. This registration is accomplished by scanning previously placed registration marks on the chip with a beam of electrons and monitoring the reflected or back-scattered electrons to determine where the beam crosses said registration marks. The method disclosed herein is a system of processing the signals encountered during beam contact with the registration marks on the chip usually at the four corners thereof, whereby the location of the marks is accurately determined. This is accomplished by first improving the signal to noise ratio of the detected signal followed by a rapid crosscorrelation between the averaged signal and another signal having certain specific and especially desirable characteristics. The final step utilizes a least squares curve fitting procedure tuned up to extract the essential parameter, that is the center of the cross-correlation, with a minimum of on-line computation.

Abstract translation: 在半导体制造中，必须在半导体材料的表面上的光致抗蚀剂中形成非常精确的图案。 利用带电粒子束在半导体晶片上形成芯片以暴露半导体表面上的光致抗蚀剂材料。 如果多个芯片具有相同的特性和图案，则必须移动带电粒子的电子束或束，使得施加光束的场内的任何点总是达到相同的历史。 这要求由电子束产生的图案相对于先前产生的图案适当地记录。 该注册通过用电子束扫描先前放置的芯片上的注册标记并监测反射或反向散射电子来确定光束穿过所述对准标记的位置来完成。 本文公开的方法是在通常在其四个角处处理在与芯片上的对准标记的光束接触期间遇到的信号的系统，由此准确地确定标记的位置。 这是通过首先改善检测信号的信噪比，然后在平均信号与具有特定和特别期望特性的另一个信号之间的快速互相关来实现的。 最后一步利用最小二乘曲线拟合程序进行调整，以最小的在线计算提取基本参数，即互相关的中心。

公开(公告)号：CA1009766A

公开(公告)日：1977-05-03

申请号：CA198075

申请日：1974-04-19

Applicant: IBM

Inventor： GILL CHARLES D ,  RYAN PHILIP M

IPC: H01J37/305 ,  G06F17/15 ,  G06F17/17 ,  G06F17/18 ,  H01J37/304 ,  H01L21/00 ,  H01L21/027

Abstract: In semiconductor manufacture, very accurate patterns must be formed in the photoresist on the surface of the semiconductor material. Chips are formed on a semiconductor wafer utilizing a beam of charged particles to expose the photoresist material on the surface of the semiconductor. If the plurality of chips, is to have the same characteristics and pattern, it is necessary that the electrons or beam of charged particles be moved such that any point within the field to which the beam is applied is always reached by the same history. This requires that patterns produced by an electron beam be properly registered with respect to previously generated patterns. This registration is accomplished by scanning previously placed registration marks on the chip with a beam of electrons and monitoring the reflected or back-scattered electrons to determine where the beam crosses said registration marks. The method disclosed herein is a system of processing the signals encountered during beam contact with the registration marks on the chip usually at the four corners thereof, whereby the location of the marks is accurately determined. This is accomplished by first improving the signal to noise ratio of the detected signal followed by a rapid cross-correlation between the averaged signal and another signal having certain specific and especially desirable characteristics. The final step utilizes a least squares curve fitting procedure tuned up to extract the essential parameter, that is the center of the cross-correlation, with a minimum of on-line computation.