次光强，用于检测和标定光栅结构的中心位置，从而实现晶圆对准要求。
[0123] S1003、利用所述第1级衍射级次光强检测和标定所述七级衍射光栅结构的中心位 置，实现晶圆光刻粗对准：
[0124] 需要说明的是，采用第1级衍射级次光强可以保证晶圆在双工作台粗对准时更加 快捷，但是其对准精度较低。
[0125] S1004、利用所述第7级衍射级次光强检测和标定所述七级衍射光栅结构的中心位 置，实现晶圆光刻精对准：
[0126] 需要说明的是，在粗对准的基础上，进一步采用第7级衍射级次光强进行请准确， 可以同时兼顾对准标记制造难易程度和精细对准时的最低精度要求。
[0127] 本说明书所描述的实施例仅仅是示意性的，本领域普通技术人员在不付出创造性 劳动的情况下，即可以理解并实施。
[0128] 以上为本发明的优选实施例，虽然本发明已以较佳实施例披露如上，然而并非用 以限定本发明。任何熟悉本领域的技术人员，在不脱离本发明技术方案范围情况下，都可利 用上述揭示的方法和技术内容对本发明技术方案作出许多可能的变动和修饰，或修改为等 同变化的等效实施例。因此，凡是未脱离本发明技术方案的内容，依据本发明的技术实质对 以上实施例所做的任何简单修改、等同变化及修饰，均仍属于本发明技术方案保护的范围 内。
【主权项】
1. 一种七级衍射光栅结构，其特征在于，包括： 晶圆； 形成于所述晶圆上的光栅图形结构； 其中，所述光栅图形结构由一个光栅精细结构单元组成或者由多个光栅精细结构单元 循环排列组成，所述光栅精细结构单元的宽度为一个光栅周期，所述光栅精细结构单元在 宽度方向上等分为28个区域，所述28个区域的每个区域上设置有第一图形结构1st或第二 图形结构2nd; 所述第一图形结构1st和第二图形结构2nd在光栅图形结构的宽度方向上按照不同顺 序排列形成不同的光栅精细结构单元，所述光栅精细结构单元为第一光栅精细结构单元、 第二光栅精细结构单元、第三光栅精细结构单元、第四光栅精细结构单元、第五光栅精细结 构单元、第六光栅精细结构单元或第七光栅精细结构单元； 所述第一光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd}； 所述第二光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 1st}； 所述第三光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd}； 所述第四光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 1st 1st}； 所述第五光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 2nd 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd}； 所述第六光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd}； 所述第七光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd}； 其中，第一图形结构1st和第二图形结构2nd在同一近邻高度位置下的光学相位相差π。2. 根据权利要求1所述的结构，其特征在于，所述晶圆为空白晶圆或者已经制作好前层 图形的晶圆。3. 根据权利要求1所述的结构，其特征在于，所述光栅周期为16微米或者17.6微米。4. 根据权利要求1-3任一项所述的结构，其特征在于，所述结构还包括： 覆盖在所述光栅图形结构上的至少一层材料层。5. -种七级衍射光栅结构的制备方法，其特征在于，包括： 提供晶圆； 对所述晶圆进行光刻和刻蚀，以在所述晶圆上形成光栅图形结构； 其中，所述光栅图形结构由一个光栅精细结构单元组成或者由多个光栅精细结构单元 循环排列组成，所述光栅精细结构单元的宽度为一个光栅周期，所述光栅精细结构单元在 宽度方向上等分为28个区域，所述28个区域的每个区域上分别设置有第一图形结构1st或 第二图形结构2nd; 所述第一图形结构1st和第二图形结构2nd在光栅图形结构的宽度方向上按照不同顺 序排列形成不同的光栅精细结构单元，所述光栅精细结构单元为第一光栅精细结构单元、 第二光栅精细结构单元、第三光栅精细结构单元、第四光栅精细结构单元、第五光栅精细结 构单元、第六光栅精细结构单元或第七光栅精细结构单元； 所述第一光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd}； 所述第二光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 1st}； 所述第三光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd}； 所述第四光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 1st 1st}； 所述第五光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 2nd 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd}； 所述第六光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 2nd 2nd 2nd 1st 1st 2nd 2nd}； 所述第七光栅精细结构单元的结构为：{1st 1st 1st 1st 1st 1st 1st 1st 1st 1st 2nd 2nd 1st 1st 2nd 2nd 1st 1st 2nd 2nd 2nd 2nd 2nd 2nd 1st 1st 2nd 2nd}； 其中，第一图形结构1st和第二图形结构2nd在同一近邻高度位置下的光学相位相差π。6. 根据权利要求5所述的方法，其特征在于，所述晶圆为空白晶圆或者已经制作好前层 图形的晶圆。7. 根据权利要求5所述的方法，其特征在于，所述光栅周期为16微米或者17.6微米。8. 根据权利要求5-7任一项所述的结构，其特征在于，所述方法还包括： 在所述光栅图形结构上覆盖至少一层材料层。9. 一种晶圆光刻对准方法，其特征在于，包括： 对权利要求1-4任一项所述的七级衍射光栅结构采用单色探测光垂直入射； 接收从所述七级衍射光栅结构中射出的反射光，并从所述反射光中分别筛选出第1级 和第7级衍射级次光强； 利用所述第1级衍射级次光强检测和标定所述七级衍射光栅结构的中心位置，实现晶 圆光刻粗对准； 利用所述第7级衍射级次光强检测和标定所述七级衍射光栅结构的中心位置，实现晶 圆光刻精对准。10. 根据权利要求9所述的方法，其特征在于，所述单色探测光的波长覆盖从可见光到 红外光的波段。11. 根据权利要求10所述的方法，其特征在于，所述单色探测光的波长为633nm、532nm、 近红外波长或远红外波长。
【专利摘要】本发明公开了一种七级衍射光栅结构及其制备方法、晶圆光刻对准方法。在该七级衍射光栅结构包括晶圆以及形成于晶圆上的光栅图形结构。光栅图形结构由光栅精细结构单元组成，光栅精细结构单元的宽度为一个光栅周期，所述光栅精细结构单元在宽度方向上等分为28个区域，每个区域上设置有第一图形结构1st或第二图形结构2nd；1st和2nd在光栅图形结构的宽度方向上按照不同顺序排列形成不同的光栅精细结构单元，所述光栅精细结构单元为第一至第七光栅精细结构单元的任一种。该光栅结构能够有效提高光栅的衍射光强，增大光刻时在对准光栅之上涂覆材料及其厚度的可选择范围，降低对准不确定性范围，提高精确对准精度。
【IPC分类】G03F9/00, G02B5/18
【公开号】CN105549138
【申请号】CN201610140991
【发明人】张利斌, 董立松, 苏晓菁, 韦亚一
【申请人】中国科学院微电子研究所
【公开日】2016年5月4日
【申请日】2016年3月11日