KR100219399B1 - A manufacturing method photomask of semiconductor - Google Patents

Abstract

Disclosed is a method of manufacturing a photomask which prevents damage to a substrate in directly etching a blank mask without a photoresist with an ion beam.

According to the present invention, a mask is configured such that a mask pattern formed by directly forming an intermediate material layer and a light blocking layer on a light transmissive substrate is formed. Further, in a photomask manufacturing method of forming a light shielding layer pattern on a blank mask comprising a light transmissive substrate and a light shielding layer, etching the pattern forming region of the light shielding layer by a predetermined depth so that the light transmissive substrate is not exposed using an ion beam and the And forming a light shielding layer pattern by etching back the entire surface of the mask to remove the light shielding layer remaining in the pattern formation region.

Therefore, the photomask can be manufactured while securing a simple and sufficient process margin while preventing damage to the substrate, thereby improving workability and improving yield and productivity.

Description

Manufacturing method of photomask for semiconductor

1A to 1E are cross-sectional views illustrating a process of manufacturing a conventional photomask for a semiconductor in general.

2A through 2C are cross-sectional views illustrating a method of manufacturing a photomask according to an embodiment of the present invention.

3A to 3C are cross-sectional views illustrating a method of manufacturing a photomask according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10,20: substrate 12,22: light shielding layer

14 photoresist 16,26 light transmission pattern

21: intermediate material layer 24: stain

Detailed description of the invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a photomask for semiconductor device manufacturing, and more particularly, to forming a mask pattern by directly irradiating a blank mask on which a light shielding layer is formed on a mask substrate to form a mask pattern. It relates to a photomask manufacturing method that prevents damage to a substrate.

In general, a photolithography process refers to transferring a predetermined pattern from a photomask or a reticle to another mask or wafer surface.

Accordingly, in order to perform the photolithography process, a pattern to be transferred must be formed on the photomask, and the photomask is a circuit in which a designed circuit is transferred on a light-transmissive substrate, and the pattern formed on the substrate is formed of an emulsion, chromium, and iron oxide thin films. Made of the same shading layer.

Conventional photomasks may be manufactured by performing a process of exposing, developing, etching, cleaning, and inspecting a blank mask in which a light shielding layer and a photoresist are sequentially stacked without patterning on a light-transmissive substrate at a predetermined thickness. have. Referring to FIGS. 1A to 1E, a conventional photomask manufacturing method will be described below.

Referring to FIG. 1A, a light blocking layer 12 such as chromium is formed on a transparent substrate 10 made of quartz, and a photoresist 14 is coated on the entire surface. Subsequently, a circuit input to a computer after being designed to perform a specific function is determined as a layout for physical representation on the wafer, and the determined layout is digitized and then controlled by a light source and a computer. A pattern generator (not shown) configured with a shutter is used to expose the photoresist 14 as in FIG. 1B to have a specific pattern as digitized.

Subsequently, as illustrated in FIG. 1C, when the exposed portion is developed and removed using a developer suitable for the characteristics of the exposed photoresist 14, a photoresist pattern to serve as an etching mask is formed.

Subsequently, as shown in FIG. 1D, the light-shielding layer 12 existing below is etched using the photoresist pattern as an etching mask to form the light-transmitting pattern 16 exposing the light-transmissive substrate 10.

Subsequently, as shown in FIG. 1E, when the unnecessary photoresist 14 coated on the light blocking layer 12 is stripped, the light blocking layer 12 made of chromium is formed on the light transmissive substrate 10. The mask in which the pattern was formed is produced.

As such, the mask in which the pattern is completed is used for wafer processing after a final inspection process for a pattern and contamination formed after removing stains and impurities through a cleaning process.

However, in the conventional general mask fabrication process, complicated processes such as light source adjustment and developer selection during exposure are required according to the type of photoresist, and etchant selection for etching and fine control of the degree of etching are required. Stripping the photoresist after etching the layer requires stringent control and selection of the stringing method and the material used, considering that the light shielding layer is a metal material such as chromium or iron oxide.

Therefore, as described above, the conventional photomask manufacturing method requires a complicated condition control process for each process, and since the workmanship is considerably large, an error occurs in the process, thereby reducing work efficiency and yield.

Accordingly, an object of the present invention is to provide a method for manufacturing a photomask for a semiconductor which can simplify the process by forming a pattern directly on the blank mask using an ion beam, thereby reducing process errors and improving workability and productivity.

Another object of the present invention is to provide a method of manufacturing a photomask for a semiconductor which prevents the substrate from being damaged by an ion beam.

In the method of manufacturing a photomask for a semiconductor according to the present invention for achieving the above object, in the method of manufacturing a photomask having a substrate and a light shielding pattern, forming a light shielding layer on the substrate is directly patterned by irradiating an ion beam to the light shielding layer. It is made with a step.

According to another aspect of the present invention, there is provided a method of manufacturing a photomask for a semiconductor, the method of manufacturing a photomask having a light shielding pattern with a substrate, the method comprising: forming a light shielding layer on the substrate; Forming a light blocking layer on the material layer, directly patterning the light blocking layer by irradiating an ion beam to expose the intermediate material layer, and etching the exposed intermediate material layer to expose the substrate.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the photomask manufacturing method according to an embodiment of the present invention will be described in detail.

(Example 1)

2A to 2C are views illustrating a process of manufacturing a photomask according to the first embodiment of the present invention. As shown in FIG. 2A, the blank mask for performing the present embodiment is different from the prior art, in which the coating layer of the photoresist prevents damage to the substrate 20 caused by the beam, and the thickness of the blank mask is etched by the FIB device. Adjust to perform appropriately.

Subsequently, when the substrate is etched back by plasma treatment, as shown in FIG. 2C, the substrate 20 is exposed to form a light transmission pattern 26 through which light can pass. Therefore, the photomask in which the pattern by the light shielding layer 22 was formed is completed.

In the above embodiment, there is no concern on the surface of the transparent substrate 20 by the ion beam, so that a high quality photomask can be manufactured and the process is very simple because the ion beam is directly irradiated on a blank mask without photoresist. There is an effect of improving productivity and yield.

(Example 2)

3A to 3C are views illustrating a process of manufacturing a photomask according to a second embodiment of the present invention. As shown in FIG. 3A, the blank mask for carrying out the present embodiment is intermediate as a mediator between the transparent substrate 20 made of quartz and the light shielding layer 22 such as chromium, without forming a coating layer of photoresist. The material layer 21 is laminated. The intermediate material layer 21 is made of argon oxide or aluminum oxide, and acts as a medium for preventing direct damage of the light-transmissive substrate 20 by ion beam, and the light shielding layer and the etching selectivity are 1: 2 or more. Any material would be possible.

As in the first embodiment described above, the ion beam for etching the light shielding layer 22 is generated by the FIB apparatus and the intermediate material layer 21 and the light shielding layer on the quartz substrate 20 as shown in FIG. 3B. On the light shielding layer 22 of the blank mask constituted by (22), the ion beam is accelerated and selectively irradiated directly according to the layout preset by the FIB apparatus.

The light blocking layer 22 irradiated with the ion beam is selectively etched according to a desired shape to form a pattern as shown in FIG. 3B by the irradiated ion beam. In this case, etching of the light blocking layer 22 is performed until the intermediate material layer 12 is exposed. Ideally, only the light blocking layer 22 can be removed if the FIB device irradiates the ion beam in the correct amount depending on the thickness of the light blocking layer 22. However, the irradiated ion beam is difficult to accurately control the amount. That is, since the ion beam has no layer selectivity, in most cases, if the amount of the ion beam is set to etch the light shielding layer 22 and the substrate 20 having a predetermined thickness, the portion of the etched light transmission pattern 26 is incompletely etched to transmit light. It becomes impossible.

However, in the present embodiment, while the intermediate layer 21 is exposed, the transmissive substrate 20 is sufficiently secured because the dose of the ion beam is determined within the range not exposed by the ion beam. On the other hand, as described above, if the light shielding layer 22 and the intermediate material layer 21 having a predetermined thickness are etched, stain 24 is generated in the etched portion as shown in FIG. 3B, but this causes damage to the surface of the transparent substrate 20. This doesn't work.

Subsequently, when the exposed intermediate material layer 21 is etched by the conventional dry or wet etching method using the patterned light blocking layer 22 as an etching mask as shown in FIG. 3C, the light-transmissive substrate 20 is formed. The exposed light-transmitting pattern 26 is formed to complete the manufacture of the desired photomask.

In the above embodiment, the damage of the substrate 20 by the ion beam having a high energy is prevented by the presence of the intermediate material layer 21, so that a high quality photomask can be manufactured and the presence of the intermediate material layer 21 This makes it possible to secure sufficient process margin for the ion beam dose control, which greatly simplifies the process and greatly increases the productivity and yield of the product.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and all such modifications and modifications belong to the appended claims. .

Claims (6)

In the method of manufacturing a photomask having a substrate and a light shielding pattern, Forming a light shielding layer on the substrate Method for manufacturing a photomask for a semiconductor, characterized in that it comprises a step of directly patterning the light-shielding layer by irradiation with an ion beam The method of claim 3, The method of manufacturing the photomask for the semiconductor, characterized in that the step of etching the light-shielding layer a predetermined time over the entire surface after directly patterning the light-shielding layer by irradiation with an ion beam. In the method of manufacturing a photomask having a substrate and a light shielding pattern, Forming a light shielding layer on the substrate Forming an intermediate material layer on the substrate Forming a light shielding layer on the intermediate material layer Directly patterning the light blocking layer by exposing an ion beam to expose the intermediate material layer; And etching the exposed intermediate material layer to expose a substrate. The method of claim 5 The intermediate material layer is a photomask manufacturing method for the semiconductor, characterized in that by removing by dry or wet etching. In the method of manufacturing a photomask having a substrate and a light shielding pattern, Forming a light shielding layer on the substrate Forming an intermediate material layer on the substrate Forming a light shielding layer on the intermediate material layer Directly patterning the light blocking layer by exposing an ion beam to expose the intermediate material layer; and And etching the exposed intermediate material layer to expose a substrate. The method of claim 5 The intermediate material layer is a photomask manufacturing method for the semiconductor, characterized in that by removing by dry or wet etching.