JPH0567595A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable normal patterning of a fine metal on a sloping surface by conducting, after formation of a deposited film on the entire surface of a substrate, anisotropic etching under the etching condition that a selection ratio for the resist is high to form the resist on the slope in such a condition that a deposited layer is buried. CONSTITUTION:After an oxide film 1 is formed on a substrate, a metal 2 is formed on the oxide film 1. Moreover, after a resist 3 is formed on the metal 2, the resist 3 is patterned. Next, a deposited film 4 is formed on the entire surface of substrate including the resist 3 after the patterning. Thereafter, a mask is formed in such a condition that a deposited film 4 is buried in a recess 5 in the lateral direction generated at the time of patterning of the resist 3 by etching the deposited film 4 under the etching condition that a selection ratio for the resist 3 is high. After etching the metal 2 using the resist 3 as a mask, the resist 3 and deposited film 4 are removed and the metal 2 is patterned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for forming a fine metal pattern.

[0002]

2. Description of the Related Art Patterning of metal is an important point in the manufacture of LSI and can be said to be a key technology for miniaturization. A conventional method will be described with reference to FIG. After forming the silicon oxide film 11 on the substrate (not shown), the metal 12 is formed on the silicon oxide film 11. Next, a resist 13 is formed on the metal 12, and the resist 13 is patterned by exposure using the mask 10. [FIG. 2 (a)]. FIG. 2B shows a state in which the resist 13 is patterned.

Next, the metal 12 is patterned by etching in the state of this resist pattern.

[0004]

However, in the conventional method, it is extremely difficult to pattern the metal particularly on the inclined surface of the base. This is because the metal has a high reflectance, and diffused reflection occurs particularly on the inclined surface, resulting in erroneous exposure, and the resist 13 is partially thinned after development as shown in FIG. 2B, which adversely affects normal patterning. give. Therefore, as shown in FIG. 2C, the patterned metal 12 does not have a normal shape, but has a partially defective defective shape. Such problems hinder the miniaturization of LSIs and reduce the reliability of the device, and therefore improvements are desired.

The present invention has been made to solve the above-mentioned problems, and it is possible to avoid abnormal etching as described above and to perform fine patterning of fine metal on an inclined surface of a semiconductor device. It is intended to provide a manufacturing method.

[0006]

According to a method of manufacturing a semiconductor device of the present invention, an oxide film is formed on a substrate, a metal is formed on the oxide film, and a resist is formed on the metal. Patterning the resist by patterning the resist and then forming a deposited film on the entire surface of the substrate including the patterned resist, and then etching the deposited film under etching conditions having a high selection ratio with the resist. It is characterized by including a step of patterning the metal by forming a mask in a state where the deposited film is embedded in a lateral concave portion generated at the time of.

[0007]

[Function] The resist patterned by exposure is
Although a concave portion is formed due to diffused reflection of the inclined surface of the metal formed under the resist, the deposited film is buried in the concave portion by forming a deposited film on the entire surface of the substrate in the next step. After that, anisotropic etching is performed under etching conditions having a high selection ratio with respect to the resist, whereby the resist on the inclined surface is formed in a state where the deposited film is embedded.

[0008]

EXAMPLE FIG. 1 is a schematic sectional view showing an example of the present invention over time. Embodiments of the present invention will be described below with reference to the drawings. After the silicon oxide film 1 is formed on the substrate (not shown) by the same method as the conventional method, the metal 2 is formed on the silicon oxide film 1. Next, a resist 3 is formed on the metal 2, and the resist 3 is exposed and patterned by using a mask (not shown). Also in this step, as described above, erroneous exposure occurs on the inclined surface due to diffused reflection of the metal 2 under the resist, so that the patterned resist 3 becomes partially thin and a recess 5 is formed [FIG. 1 (a)]. ].

After that, the SOG is formed on the entire surface of the substrate in the above-mentioned state.
4 (Spin On Glass) is spin-coated, and this SOG4 is dried and cured at a predetermined temperature. By this step, the SOG 4 is filled in the portion where the resist 3 is removed, that is, the recess 5 [FIG. 1 (b)]. Then, the SOG 4 is anisotropically etched over the entire surface under an etching condition having a high selection ratio with respect to the resist 3, so that the SOG in the recess 5 is etched.
4 is in a buried state, and the resist 3 is patterned again [FIG. 1 (c)].

Then, the resist 3 formed in this way
After the metal 2 is etched using the mask as a mask, the resist 3 and the SOG 4 are removed.
Patterning is completed [FIG. 1 (d)]. In the embodiment of the present invention, SOG is used as the deposited film that fills the recess 5 formed in the resist 3. However, if the step coverage is not limited to this SOG, for example, PSG or P-
You may use SiN etc.

According to the above method, the portion where the resist 3 is removed by being erroneously exposed due to the reflection on the inclined surface is filled with SOG4. 2 patterning can be performed.

[0012]

As described above, according to the present invention, a resist portion that is partially chipped or thinned due to erroneous exposure is filled with SOG to form a resist having a normal shape. Therefore, fine patterning of a metal having an inclination can be favorably performed. As a result, the miniaturization of the LSI can be easily performed, and the reliability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram illustrating a conventional example.

[Explanation of symbols]

 1 ... ・ Silicon oxide film 2 ・ ・ ・ ・ ・ ・ Metal 3 ・ ・ ・ ・ ・ ・ Resist 4 ・ ・ ・ ・ SOG

Claims (1)

[Claims] 1. An oxide film is formed on a substrate, a metal is formed on the oxide film, a resist is formed on the metal, the resist is patterned, and then the patterned resist is included. After the deposited film is formed on the entire surface of the substrate, the deposited film is etched under an etching condition having a high selection ratio with the resist, so that the deposited film is formed in the concave portion in the lateral direction generated during the patterning of the resist. Form a mask with the embedded
A method for manufacturing a semiconductor device, comprising the step of patterning the metal.