BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart of a process for manufacturing a broad stamper according to an embodiment of the invention.
FIG. 2 is a flow diagram of a process for manufacturing a broad stamper according to an embodiment of the invention.
DETAILED DESCRIPTION
The method of manufacturing a broad stamper according to certain embodiments of the invention will be described below in more detail with reference to the accompanying drawings, in which those components are rendered the same reference numeral that are the same or are in correspondence, regardless of the figure number, and redundant explanations are omitted.
FIG. 1 is a flowchart of a process for manufacturing a broad stamper according to an embodiment of the invention, and FIG. 2 is a flow diagram of a process for manufacturing a broad stamper according to an embodiment of the invention. In FIG. 2 are illustrated a broad stamper 20, a positive photoresist layer 21, a substrate 22, a first mask 23a, a second mask 23b, a first exposure portion 24a, a second exposure portion 24b, a molding portion 25, a first pattern 26a, a second pattern 26b, an intaglio 27, and a relievo 28.
Operation S11 of FIG. 1 may be to stack the first mask 23a, in which the first pattern 26a is formed, on the positive photoresist layer 21, where drawings (a) and (b) of FIG. 2 represent processes related to this operation.
The positive photoresist layer 21 refers to the part where the portions exposed to light are removed, and the positive photoresist layer 21 of this embodiment, in particular, may have a property that those portions exposed to light become transparent.
The first pattern 26a may be formed in the first mask 23a. The first pattern 26a may be the portion where the first mask 23a is perforated. The first pattern 26a of the first mask 23a may determine the position where a circuit pattern will be formed later on.
Since the positive photoresist layer 21 by itself may be lacking in strength, the positive photoresist layer 21 may be stacked on the substrate 22, which will support the positive photoresist layer 21, before proceeding with the process. While the material for the substrate may be glass, quartz, or silicon, etc., it is not thus limited, and other materials may be used, such as metallic materials.
Operation S12 of FIG. 1 may be to expose the upper surface of the first mask 23a to light, where drawing (c) of FIG. 2 represents a process related to this operation. As illustrated in (c) of FIG. 2, when UV rays are irradiated, the portion of the positive photoresist layer 21 receiving the rays may become transparent. This portion will hereinafter be referred to as the “first exposure portion.” The first exposure portion 24a is the portion that will be removed later on. In order to form a pattern of multiple levels, it may be necessary to adjust the thickness of the first exposure portion 24a, where the adjusting method may include adjusting the intensity and time of light exposure.
Operation S13 of FIG. 1 may be to stack the second mask 23b, where drawing (d) of FIG. 2 represents a process related to this operation. While it may be considered to remove the first mask 23a before operation S13, the operation may be proceeded without removing the first mask 23a. The reason for proceeding with such an operation may be to form a multi-level intaglio 27 in the positive photoresist layer 21.
When the second mask 23b is stacked as in (d) of FIG. 2, the second pattern 26b of the second mask 23b may have a size smaller than that of the first pattern 26a in the first mask 23a. This is so that the first exposure portion 24a formed by the first pattern 26a will not be affected by the exposure to light for the second pattern 26b. In other words, as the second pattern 26b may be for forming an intaglio 27 with a greater depth, it may not be desirable to distort the first exposure portion 24a.
Operation S14 of FIG. 1 may be to expose the upper surface of the second mask 23b to light, where drawing (e) of FIG. 2 represents a process related to this operation. When the exposure is proceeded with as in (e) of FIG. 2, the second exposure portion 24b may be formed. Since the positive photoresist layer 21 may change to a transparent substance when exposed to light, the irradiated UV rays may be transmitted through the transparent first exposure portion 24a to form the second exposure portion 24b. As the size of the second pattern 26b may be smaller than the size of the first pattern 26a, the first exposure portion 24a and second exposure portion 24b form a multi-leveled configuration.
Operation S15 of FIG. 1 may be to remove and develop the second mask 23b. The portions of the positive photoresist layer 21 exposed to light may be developed, so that the developing process may remove the first exposure portion 24a and second exposure portion 24b. Consequently, a positive photoresist layer 21 may be obtained in which an intaglio 27 is formed, as in (g) of FIG. 2.
Operation S16 of FIG. 1 may be of molding such that the relievo 28 is formed which corresponds to the intaglio 27 of the positive photoresist layer 21, where drawing (g) of FIG. 2 represents a process related to this operation.
A procedure of curing the positive photoresist layer 21 may also be performed before operation S16. The positive photoresist layer 21 may have a generally low strength, and may thus be unsuitable for molding work. Therefore, by performing such a curing process, the molding work of operation S16 may be facilitated.
The molding may be performed using nickel electroforming or using polymers. However, other materials may just as well be used, as long as they ensure a certain degree of hardness and reliability in use in a stamper.
With the removal of the positive photoresist layer 21 and the substrate 22, the broad stamper 20 may be completed. The broad stamper 20 may have the relievo 28 formed therein. This relievo 28 may have a form that is in correspondence with the intaglio 27 of the positive photoresist layer 21.
According to a certain aspect of the claimed invention as set forth above, a broad stamper having multiple levels can be manufactured with a simple process, by using a positive photoresist layer and a plurality of masks in which patterns are formed.
While the spirit of the invention has been described in detail with reference to particular embodiments, the embodiments are for illustrative purposes only and do not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the invention.
Patent Application
20080057444
