次光強，用于檢測和標定光柵結構的中心位置，從而實現晶圓對準要求。
[0123] S1003、利用所述第1級衍射級次光強檢測和標定所述七級衍射光柵結構的中心位 置，實現晶圓光刻粗對準：
[0124] 需要說明的是，采用第1級衍射級次光強可以保證晶圓在雙工作臺粗對準時更加 快捷，但是其對準精度較低。
[0125] S1004、利用所述第7級衍射級次光強檢測和標定所述七級衍射光柵結構的中心位 置，實現晶圓光刻精對準：
[0126] 需要說明的是，在粗對準的基礎上，進一步采用第7級衍射級次光強進行請準確， 可以同時兼顧對準標記制造難易程度和精細對準時的最低精度要求。
[0127] 本說明書所描述的實施例僅僅是示意性的，本領域普通技術人員在不付出創造性 勞動的情況下，即可以理解并實施。
[0128] 以上為本發明的優選實施例，雖然本發明已以較佳實施例披露如上，然而并非用 以限定本發明。任何熟悉本領域的技術人員，在不脫離本發明技術方案范圍情況下，都可利 用上述揭示的方法和技術內容對本發明技術方案作出許多可能的變動和修飾，或修改為等 同變化的等效實施例。因此，凡是未脫離本發明技術方案的內容，依據本發明的技術實質對 以上實施例所做的任何簡單修改、等同變化及修飾，均仍屬于本發明技術方案保護的范圍 內。
【主權項】
1. 一種七級衍射光柵結構，其特征在于，包括： 晶圓； 形成于所述晶圓上的光柵圖形結構； 其中，所述光柵圖形結構由一個光柵精細結構單元組成或者由多個光柵精細結構單元 循環排列組成，所述光柵精細結構單元的寬度為一個光柵周期，所述光柵精細結構單元在 寬度方向上等分為28個區域，所述28個區域的每個區域上設置有第一圖形結構1st或第二 圖形結構2nd; 所述第一圖形結構1st和第二圖形結構2nd在光柵圖形結構的寬度方向上按照不同順 序排列形成不同的光柵精細結構單元，所述光柵精細結構單元為第一光柵精細結構單元、 第二光柵精細結構單元、第三光柵精細結構單元、第四光柵精細結構單元、第五光柵精細結 構單元、第六光柵精細結構單元或第七光柵精細結構單元； 所述第一光柵精細結構單元的結構為：{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}； 所述第二光柵精細結構單元的結構為：{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}； 所述第三光柵精細結構單元的結構為：{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}； 所述第四光柵精細結構單元的結構為：{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}； 所述第五光柵精細結構單元的結構為：{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}； 所述第六光柵精細結構單元的結構為：{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}； 所述第七光柵精細結構單元的結構為：{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，第一圖形結構1st和第二圖形結構2nd在同一近鄰高度位置下的光學相位相差π。2. 根據權利要求1所述的結構，其特征在于，所述晶圓為空白晶圓或者已經制作好前層 圖形的晶圓。3. 根據權利要求1所述的結構，其特征在于，所述光柵周期為16微米或者17.6微米。4. 根據權利要求1-3任一項所述的結構，其特征在于，所述結構還包括： 覆蓋在所述光柵圖形結構上的至少一層材料層。5. -種七級衍射光柵結構的制備方法，其特征在于，包括： 提供晶圓； 對所述晶圓進行光刻和刻蝕，以在所述晶圓上形成光柵圖形結構； 其中，所述光柵圖形結構由一個光柵精細結構單元組成或者由多個光柵精細結構單元 循環排列組成，所述光柵精細結構單元的寬度為一個光柵周期，所述光柵精細結構單元在 寬度方向上等分為28個區域，所述28個區域的每個區域上分別設置有第一圖形結構1st或 第二圖形結構2nd; 所述第一圖形結構1st和第二圖形結構2nd在光柵圖形結構的寬度方向上按照不同順 序排列形成不同的光柵精細結構單元，所述光柵精細結構單元為第一光柵精細結構單元、 第二光柵精細結構單元、第三光柵精細結構單元、第四光柵精細結構單元、第五光柵精細結 構單元、第六光柵精細結構單元或第七光柵精細結構單元； 所述第一光柵精細結構單元的結構為：{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}； 所述第二光柵精細結構單元的結構為：{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}； 所述第三光柵精細結構單元的結構為：{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}； 所述第四光柵精細結構單元的結構為：{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}； 所述第五光柵精細結構單元的結構為：{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}； 所述第六光柵精細結構單元的結構為：{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}； 所述第七光柵精細結構單元的結構為：{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，第一圖形結構1st和第二圖形結構2nd在同一近鄰高度位置下的光學相位相差π。6. 根據權利要求5所述的方法，其特征在于，所述晶圓為空白晶圓或者已經制作好前層 圖形的晶圓。7. 根據權利要求5所述的方法，其特征在于，所述光柵周期為16微米或者17.6微米。8. 根據權利要求5-7任一項所述的結構，其特征在于，所述方法還包括： 在所述光柵圖形結構上覆蓋至少一層材料層。9. 一種晶圓光刻對準方法，其特征在于，包括： 對權利要求1-4任一項所述的七級衍射光柵結構采用單色探測光垂直入射； 接收從所述七級衍射光柵結構中射出的反射光，并從所述反射光中分別篩選出第1級 和第7級衍射級次光強； 利用所述第1級衍射級次光強檢測和標定所述七級衍射光柵結構的中心位置，實現晶 圓光刻粗對準； 利用所述第7級衍射級次光強檢測和標定所述七級衍射光柵結構的中心位置，實現晶 圓光刻精對準。10. 根據權利要求9所述的方法，其特征在于，所述單色探測光的波長覆蓋從可見光到 紅外光的波段。11. 根據權利要求10所述的方法，其特征在于，所述單色探測光的波長為633nm、532nm、 近紅外波長或遠紅外波長。
【專利摘要】本發明公開了一種七級衍射光柵結構及其制備方法、晶圓光刻對準方法。在該七級衍射光柵結構包括晶圓以及形成于晶圓上的光柵圖形結構。光柵圖形結構由光柵精細結構單元組成，光柵精細結構單元的寬度為一個光柵周期，所述光柵精細結構單元在寬度方向上等分為28個區域，每個區域上設置有第一圖形結構1st或第二圖形結構2nd；1st和2nd在光柵圖形結構的寬度方向上按照不同順序排列形成不同的光柵精細結構單元，所述光柵精細結構單元為第一至第七光柵精細結構單元的任一種。該光柵結構能夠有效提高光柵的衍射光強，增大光刻時在對準光柵之上涂覆材料及其厚度的可選擇范圍，降低對準不確定性范圍，提高精確對準精度。
【IPC分類】G03F9/00, G02B5/18
【公開號】CN105549138
【申請號】CN201610140991
【發明人】張利斌, 董立松, 蘇曉菁, 韋亞一
【申請人】中國科學院微電子研究所
【公開日】2016年5月4日
【申請日】2016年3月11日