JPS6164127A - X-ray exposure - Google Patents

Abstract

PURPOSE:To make possible to be high throughput X-ray exposure by a method wherein a P type X-ray resist is applied to a substance to be processed and X-ray projects wholly on the substance to be processed, consequently X-ray copy using X-ray mask is performed. CONSTITUTION:At first, a P type X-ray resist 2 is applied on a substance to be processed 1. Secondarily, on the substance to be processed 1 which is applied by the P type X-ray resist, the X-ray is projected wholly using a X-ray source 3. Additionally, a X-ray projection (exposure) is performed to necessary region on the substance to be processed 1, which is applied by the P type X-ray resist 2, with the use of a X-ray mask 8 which is composed with a X-ray transmission section 5, a X-ray absorber pattern 6 and substrate 7, and the X-ray source 3. By this fact, high throughput X-ray exposure is enabled using the practical P type X-ray resist.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an X-ray exposure method in the field of X-ray phosphorography, which is effective for copying fine/4' turns of 1 μm or less.

(Prior technology) X-ray exposure technology is expected to be an extremely promising copying technology in the future due to its reliable high resolution of 4 turns of submicron width, and active research and development is currently being carried out in various places. ing.

FIG. 3 shows a basic conceptual diagram of conventional X-ray exposure. A similar diagram appeared in the 1972 publication Electronics Letters (El@ctronics L@
tters) Vol. 8, No. 4, pp. 102-104. X-rays 32 emitted from the X-ray source 31 pass through the X-ray transmitting portion 34 of the X-ray mask 33 and are irradiated onto the X@resist 36 coated on the workpiece 35. At this time
X-rays do not pass through the X-ray absorber pattern section 37 formed on the radiation-transmissive section, so that it functions as a mask/four turns.

(Problems to be solved by the invention) Since the basic method for X-ray exposure shown in Figure 3 was announced,
Although much research and development has been carried out to date, this system, which is an 1:1 copying technique, is the fundamental principle. Until now, individual technologies such as X-ray sources, alignment methods and devices, X-ray masks, and X-ray resists have been actively researched and developed, and the X#i! There are several types of exposure systems that can be used. Although it can be said that the practical application of X-ray exposure technology is just being realized, the biggest problem at present and in the future will be throughput. The factors that determine throughput in X-ray exposure are the intensity of the X-ray source and the associated sensitivity of the X-ray resist. In other words, the electron beam excitation X-ray source, which is often used in ordinary stages, has an extremely low conversion efficiency of electron beam output to X-rays of ~1O-4 and is a diverging light source, so the irradiation intensity at the exposed part is Very weak.

A plasma X-ray source that is expected to be a high-brightness X-ray source)
The conversion efficiency of -9 Lus to X-rays is as high as 10-2 with a 4 Lus source, but the development of a long-life switch circuit was necessary to prevent various damage when the Lus occurs and the generation of electrical delta Luss. , and repetition rate), many problems must be solved for practical use. Furthermore, in the case of synchrotron orbital radiation sources, the development of which has recently gained momentum, there are high expectations as they can provide high-intensity parallel beams, but they are still in the early stages of development.) It is probably too early to discuss gender. Therefore, regarding X-ray sources, it can be said that at present, the most classical and well-proven electron beam excitation source is optimal for practical-level X-ray exposure apparatuses. In this regard, particularly when using an electron beam excitation source, a high sensitivity of the X-ray resist is required. 1 to get enough slugs
It is essential to develop a highly sensitive X-ray resist of 0 mJ/cIIL2 or less. By the way, such a highly sensitive and practical X-ray resistor is hardly found at present. X!
! Considering the history of resist development, the sensitivity is 10 mJ/c.
It is thought that a long development period will be required in order to obtain something that can withstand the production of practical devices with a size of less than m''.

One of the most necessary elements in the practical performance of a general exposure apparatus is throughput, and as mentioned above, improving throughput is also an important issue in X-ray exposure technology.

An object of the present invention is to eliminate such conventional problems and to develop a new Xff that enables high-throughput X-ray exposure.
The purpose of the present invention is to provide a new X-ray exposure method that enables laM light. (Means for solving the problems)
In the exposure method, a positive X-ray resist is applied to the workpiece, the entire surface of the workpiece is irradiated with X-rays, and then the Xa-ray resist is applied to the workpiece. This is an xfIA exposure method characterized by performing X-ray copying using a ray mask.

(Example) The configuration of the present invention will be described below with reference to the drawings. FIGS. 1(&) to (c) are schematic diagrams showing an embodiment of the X,@ exposure method according to the present invention. First, Figure 1 (,
), as a first step, a digital X-ray resist 2 is applied onto the workpiece 1. Next, in Figure 1(b),
In the second step, the entire surface of the workpiece 1 coated with the digital X-ray resist is irradiated with X-rays 4 using the X-ray source 3. Furthermore, as a third step, as shown in FIG. X-ray irradiation (exposure) is performed on a required area on the workpiece l coated with the digital X-ray resist 2 using the X-ray mask 8 and the X-ray source 3, which are composed of the X-ray mask 8 and the support part 7. . The above is the basic configuration of the present invention, and its principle is shown in Figures 2 (a) and (b).
Explain using. The figure shows the sensitivity characteristics of a positive X-ray resist as a relationship between the residual film rate and the X-ray dose.

Figure 2 (,) shows the X under the X-ray transmission area of the X-ray mask.
FIG. 2(b) shows the sensitivity characteristics of the X-ray resist under the four turns of the X-ray absorber. It is assumed that a dose of Dl is applied to the X-ray resist by irradiating the entire surface with X-rays as shown in FIG. This Dl is the sensitivity DOo (
The dose amount at which the thickness after development becomes zero) is set to a smaller value. Although Dl is shown in FIGS. 2(a) and (b), the same dose is given because the entire surface is irradiated with X-rays without an X-ray mask. Next, the process moves to X-ray exposure using the X-ray mask shown in FIG. 1(c). At this time, the second
In the case of Figure (a), an X-ray dose D2 that exceeds the sensitivity D0 is given to the XM Resist, and in the case of Figure 2 (b), an X-ray dose D3 that is smaller than the sensitivity D0 and larger than D2 is given to the XM Resist. settings are possible. The X-ray dose of D3 means the irradiation of the X+'J resist by a small amount of X-rays that have passed through the four-turn section of the X-ray absorber. In other words, in the case of (,), the X-ray dose of Dl is given to the X-ray resist in the -th time, the X-ray dose of (D2-D, ) is given to the X-ray resist in the second time, and in the case of (b), is -
In the second time, the Xa dose is (D5-Dl).
) will be applied to the X-ray resist.

In this way, it is possible to obtain a round copy no-turn in which the residual film ratio is 1 in the X-ray absorber no-turn part and the residual film ratio is 1 in the X-ray transmissive part.

In the above explanation, it can be considered that the first full surface irradiation with Xi apparently improves the sensitivity of the top-bottomed X-ray resist by subtracting Dl. That is, the sensitivity has changed from Do to (Do-Dl). Therefore, according to the present invention, it is considered that the sensitivity of the X-ray resist can be greatly improved by two X-ray exposures. Moreover, these two X-ray exposures can be processed in parallel by providing a plurality of apparatuses (one may be only an X-ray source system). This means that the throughput can be greatly improved.

By preparing a large number of workpieces coated with a top-shaped X-ray resist that has been fully irradiated with X-rays and performing Xa exposure using an X-ray mask, the exposure time can be greatly shortened, that is, a high throughput can be achieved. It will be done.

Note that when considering the Bottled X-ray resist used in the present invention, the r value is more important than the sensitivity. That is, the higher γ resist allows the apparent sensitivity (Do-Dl) to be much smaller.

(Effects of the Invention) As explained above, according to the present invention, firstly, high-throughput X-ray exposure using a practical positive-type X-ray resist is possible, and secondly, a bottom-type X-ray resist has been developed. Thirdly, the development of a practical X-ray exposure system using an electron beam-excited X-ray source, etc. can be achieved at an early stage. This has the effect of realizing commercialization.

[Brief explanation of drawings]

Figures 1 (a), (b), and (C) are schematic diagrams for explaining step-by-step an X-ray exposure method according to an embodiment of the present invention, and Figures 2 (a) and (b) are FIG. 3 is a conceptual diagram of conventional X-ray exposure, which is a diagram showing the relationship between the residual film rate and the X-ray dose, which will be explained in detail in the present invention. 1... Workpiece, 2... Bot type X-ray resist, 3...
...X-ray source, 4...X-ray, 5...X-ray transmission section, 6.
... X-ray absorber turn part, 7... Support part, 8...
・X-ray mask. Figure 1 (α) (C) (α) × Benchen dose (b) Chikarasen dose

Claims (1)

[Claims] (1) In an X-ray exposure method in which a workpiece coated with an X-ray resist is irradiated with X-rays emitted from an X-ray source through an X-ray mask, a positive X-ray resist is applied on the workpiece. An X-ray exposure method characterized in that the entire surface of the workpiece is irradiated with X-rays, and then X-ray copying is performed using the X-ray mask.