JPS58168231A - Etching method in preparation of semiconductor device - Google Patents

Abstract

PURPOSE:To amplify an etching end signal, and easily and accurately monitor the end of etching by enlarging the etching area by removing the resist at the wafer area which does not become a product. CONSTITUTION:A hard mask A is produced by vacuum depositing a chrome film 2 on a glass substrate 1 in such a way that the periphery of mask pattern 3 which is smaller than wafer 4 is perfectly covered by said chrome, and it is then stacked, through positioning, on the wafer 4 on which negative photo resist 5 is coated and then exposing is carried out. Since the corresponding part 5A on the wafer 4 at the external side of pattern 3 is not exposed, such part is removed by developing process. In case of executing the etching SiO2 using CHF2 as the etching gas, since the etching area is expanded, amount of CO generated increases and light emitting intensity of plasma changes largely at the end of etching.

Description

Detailed Description of the Invention (1) MIiOal1 Field This article relates to the etching method in the conductor device OS fabrication, and in more detail, Hiroko ν tender 1) @ point detection to make it a pest and large semiconductor device O fabrication. According to the Eratin 1 method.

(2) TECHNOLOGY 11011' Background With the increasing performance and high integration of semiconductor devices, mold face delta turn formation a technology has become important as a basic process technology in manufacturing technology, and interim development of OvL is progressing. It is being The mold 1Δ turn formation technology is based on the photoresist/4p-n by photoembroidery technique 111.
Zat! Semiconductor %P, which is necessary for the element as a mask, is etched with a metal metallurgy chemical prefecture crystal in the P body.
It was defeated by the intimidating Tech V and Chidani Yang. .

At the main meeting of Mold IsA**, the most commonly used technology for engineering and processing is chemical dilutions based on marrow water S*! 17-How to deal with pharmaceuticals? Inconvenience, anxiety, etc., in the area, water-soluble sprays are used, and do not use water-soluble sprays.
The nine-dot etching technology used in the industry has been attracting attention and is being put to practical use. Dry niche y da is O plasma-ex in vacuum
With nine reactions using the ΔIvy Reaction Society, - Improvement of Kusotaka, Automation during the simplification and bulking of Engineering @O, and Mukai Yasukura! There is Kamu J'011m. By using such a technique (such as this), it is possible to accurately know the end point of etching O in the above-mentioned Dreyer and Chinda.
Jin and Ami are indispensable.

<3) Due to the lack of Ii technology, for example, when etching is performed in the ninth step to form a contact hole with a source/drain, the etching area is small. In the method of determining the end point of etching O by the change in the etching luminescence intensity O, the end point of etching can be detected by rounding, which has little change.
For this reason, there is a drawback that it is difficult to obtain a resist Δ turn with good dimensional accuracy.

(4) The purpose and structure of the INO should be rounded to take into account this situation and clearly know the end point of the etching. The etching area is expanded by removing the resist from a portion of the wafer beforehand.

The basis for applying the present invention to this 15th theory is as follows.
j), that is, for example, etching gas is CI!
y, using 810. I'm working on it! , C1[F,
Dissociate in plasma: CCF, medium M and deposit 01110 on the wafer. It is thought that it reacts with C0,81F4* to produce C0,81F4*. Of these, CO has a wavelength fi of 04 nm.
I & party. ζO party strength is just etching (Jl
) Expanded with 0 and value, the previous 0fi5 was strong and the end point was detected Kjllll
Due to the long time, the luminous intensity of 0604 in front of Jl is high when the amount of COO is large, and the curved and rounded 8-01 side is wide. ), it becomes easier to detect the end point O. In this way, if the KIiO, image, that is, the etching IN not covered by the register, is wide, it is easy to detect the end point. It is clear that this holds true when the end point is detected by .

In order to widen the eratin/l1llt, for example, a part of the resist that will not be used as a product may be applied before the etching. For this purpose, a separate mask may be used as described in the examples. Hereinafter, one embodiment of the present invention will be explained based on the drawings.

(5) Example Tam on the glass substrate 1! is vapor-deposited to produce a bary mask. ζO area, wafer 4 to be described later) is also placed on such a hard mask wafer 4, which has a small area and is deposited so that the entire surface of the mask Δta is completely covered with chromium. Combine and overlap both.

A negative photoresist S is coated on the wafer 4.

Next, exposure is carried out.In this example, positional exposure is performed, but exposure is not carried out using the ζO method, but using the working method, for example, the same method (projection exposure using a Q-r tube). , or the method of printing the image of the reticle in units of 1000 pixels (Step Pv Beat Exposure) is also slow to use.If you use m light in a state where the rattan mm1K is displayed, the i-screw Δturn sO extrapolation will be delayed. The upper part of the wafer t@image tK is not exposed because it is not exposed to light and is not cured by photopolymerization.

In this example, the outer part of the master pattern 30 and the corresponding part 5 on the wafer 4 are not exposed. and removes partials that are not covered by photoresist.

In this example, the 4-resilicon process was performed under the following conditions: etching gas car, 100G, flow rate 150
1177 minutes, stage temperature 30℃, degree of vacuum 0, 3T@
rr s Wafer diameter 4 inches High frequency output 800W'e
The turning, machining, and chinda motor were performed using the following method.

Stone J [Put one end of the optical fiber outside chamber O at 11]
A spectroscope is attached to the other end to emit a 604 mm beam, and a tiglare is attached at the end of the track to convert the intensity changes into electrical signals.

Test results 1114 As shown in Figure 4, when this method was used in nine cases (indicated by curve a in 1!l), in the case of the conventional method' (indicated by -11 in -11), ), the amount of signal change before and after just etching varies, making it easier to detect the end point.

Note that for the measurement, light with a wavelength of approximately 604 nm was used.

In the wooden figurine, the etching area is expanded compared to that in the conventional wood figurines, so the amount of cook that occurs frequently in the wood figurines increases, and the luminescence intensity becomes stronger.

Therefore, the change in the emission intensity of the plasma source at the end of etching becomes relatively large.

(6) Effects of the invention As explained above, the present invention provides a
By applying s resist to Wk*,
Since it is configured to enlarge S, the end point signal of etching is essential, and the etching end f: can be easily and reliably monitored by -i. Therefore, it is possible to obtain the effect of forming a moldy nolin by such an etching method.

[Brief explanation of drawings]

Diagram 1 of the irises is Plane-1 showing a mask used in an embodiment of the present invention. Diagram 2 of the rattan is a 1000-page diagram showing a mask used in an embodiment of the present invention. Iris Saa is a plane-1 diagram showing a mask used in an embodiment of the present invention. J1411 is a graph showing the overlapping state of the mask and wafer used in the above. DESCRIPTION OF SYMBOLS 1...Glass substrate, 2-...Chromium metal, 3...Mask vine 7, 4...Wafer, 5-...Nef#M photoresist, M...Hard mask. License applicant: Fujitsu Ltd. License application agent, hired attorney, Aoki Amiben, illustrated by Shioji Amiben, - Kazunoben 1±-j'i ii, Ikedo Yamaguchi, illustration 4

Claims (1)

[Claims] 1. The etching method in the conductor device O-resist is characterized by enlarging the elastin/m11m by removing a part of the surface (on the surface of the surface) before etching.