METHOD OF ENHANCING GENERATION EFFICIENCY OF PATTERNED OPTICAL COATING

Abstract

A method of enhancing generation efficiency of patterned optical coating is disclosed. When an exposure and development process is performed after a photoresist process on the silicon wafer, a dummy pattern is formed on a scribe line around a chip as a sacrificial layer. After an optical coating process is completed, the dummy pattern from the photoresist to be removed can be selected as the starting point of a photoresist lift-off process, such that the photoresist removal can be more efficient and accurate, and the generation efficiency of patterned optical coating is enhanced.

Claims

1. A method of enhancing generation efficiency of patterned optical coating, comprising: wafer cleaning process: cleaning a silicon wafer with a plurality of chips separated by scribe lines; photoresist coating process: forming a photoresist layer the surface of said silicon wafer to cover the plurality of chips; exposure and development (including dummy pattern) process: by using an optical exposure system to form line patterns of the photoresist layer on said silicon wafer; optical coating process: coating an optical film on the surface of each of line pattern and the exposed chips; and photoresist removal process: removing the line patterns of the photoresist layer by using a photoresist lift-off process and keep the coated optical film on the surface of chips; characterized in that: in the exposure and development (including dummy pattern) process, when the line patterns of the photoresist layer are formed on said silicon wafer, a dummy pattern is also formed on the scribe lines around the chip as the lift-off start point of the photoresist removal process.

2. The method of enhancing generation efficiency of patterned optical coating as claimed in claim 1, wherein the width of the dummy pattern is 1-80 m.

3. The method of enhancing generation efficiency of patterned optical coating as claimed in claim 1, wherein the dummy pattern is a sacrificial layer for implementing the photoresist removal process.

4. The method of enhancing generation efficiency of patterned optical coating as claimed in claim 3, wherein the dummy pattern can be a grid pattern, a square pattern, a circle pattern, a triangle pattern, or other patterns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a cross-sectional view showing a conventional semiconductor patterned process flow;

[0012] FIG. 2 is a schematic view showing a conventional silicon wafer coated with photoresist;

[0013] FIG. 3 is a flowchart showing steps in a method of enhancing generation efficiency of patterned optical coating according to the present invention;

[0014] FIG. 4 is a cross-sectional view showing the flow of the method of enhancing generation efficiency of patterned optical coating in the present invention;

[0015] FIG. 5 is a plan view of wafer configuration according to the method of enhancing generation efficiency of patterned optical coating in the present invention;

[0016] FIG. 6A is a plan view of silicon wafer according to the method of enhancing generation efficiency of patterned optical coating in the present invention;

[0017] FIG. 6B is an enlarged view showing part A of FIG. 6A;

[0018] FIG. 7 is a schematic diagram showing the dummy pattern in the method of enhancing generation efficiency of patterned optical coating according to the present invention is a grid pattern;

[0019] FIG. 8 is a schematic diagram showing the dummy pattern in the method of enhancing generation efficiency of patterned optical coating according to the present invention is a square pattern;

[0020] FIG. 9 is a schematic diagram showing the dummy pattern in the method of enhancing generation efficiency of patterned optical coating according to the present invention is a circle pattern; and

[0021] FIG. 10 is a schematic diagram showing the dummy pattern in the is method of enhancing generation efficiency of patterned optical coating according to the present invention is a triangle pattern.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] A method of enhancing generation efficiency of patterned optical coating in the present invention, as shown in FIGS. 3 and 4, includes: (a) wafer cleaning process 100: cleaning the surface of a silicon wafer 21; (b) photoresist coating process 200: using a spin coater for wafer vacuum suction, and then dropping a photoresist solution from above to form a photoresist layer 22 on the surface of the silicon wafer; (c) exposure and development (including dummy pattern) process 300: with an optical exposure system, irradiating a mask with UV light and then projecting it onto the photoresist layer, such that the chemical bonds of some photoresists are damaged, and a lens group in the optical exposure system projects the pattern on the mask onto the silicon wafer 21 to farm a line pattern 23 on the photoresist layer of the silicon wafer; (d) optical coating process 400: through an evaporation process, an optical film 25 is coated on the surface of the line pattern 23 and the exposed chip 24; and (e) photoresist removal process 500: using the photoresist solution to dissolve and remove the remaining photoresist on the silicon wafer so that the surface of the silicon wafer 21 only keeps the necessary optical film 25.

[0023] Please refer to FIG. 5. In the method of enhancing generation efficiency of patterned optical coating of the present invention, the outer of each chip 24 is provided with a scribe line 31, and at least one sensor 26 is provided inside the chip 24. The upper surface of each sensor 26 is coated with the optical film 25. After the optical film 25 is coated, each chip 24 is separated by the scribe line 31, and the optical film 25 coated on the chip 24 is sized to be within the specification. For example, the distance (A) between the optical film 25 and the pad 101 should be equal to or greater than 80 m, the width (B) of the reaction region within the optical film 25 should be equal to or greater than 50 m, the width (C) of the optical film 25 should be equal to or greater than 100 m, and the gap (D) between the two optical films 25 should be equal to or greater than 50 m, etc.

[0024] As shown, in the method of enhancing generation efficiency of patterned optical coating of the present invention, a dummy pattern 600 is formed on the scribe line 31 around the chip 24. The dummy pattern 600 is formed on the scribe line 31 simultaneously with the exposure and development (including dummy pattern) process 300. The dummy pattern 600 may be formed in different line types, mainly served as a sacrificial layer.

[0025] Please refer to FIGS. 6A and 6B. When the photoresist layer 22 is removed by a photoresist lift-off process after each chip on the silicon wafer 21 is coated with the optical film 25, any dummy pattern 600 provided on the scribe line 31 may be used as a lift-off start point, removing the photoresist around the optical film 25 nearby so that the photoresist at any position can be reliably removed in one operation.

[0026] According to the method of enhancing generation efficiency of patterned optical coating in the present invention, the type of the dummy pattern 600 can be a grid pattern 601. (as shown in FIG. 7), a square pattern 602 (as shown in FIG. 8), a circle pattern 603 (as shown in FIG. 9), a triangle pattern 604 (as shown in FIG. 10) or other patterns. The width of the dummy pattern 600 is preferably 1-80 m.

[0027] The described are merely preferred embodiments in the present invention. However, the structural features of the present invention are not limited thereto, and changes and modifications may be made to the described embodiments without departing from the scope of the invention as disposed by the appended claims.