JPH0114025Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry etching apparatus for developing resist on a substrate surface using plasma gas.

In recent years, there has been a strong trend toward dry manufacturing processes for semiconductor integrated circuits. In particular, the etching process is being made dry using various methods such as plasma etching and reactive ion beam etching.
Etching with less side etching is now possible. In contrast, most of the current resist development is wet-type. However, this wet development cannot avoid swelling deformation in which the resist absorbs the developer and the resist pattern is deformed when it dries. For this reason, recently, dry development using gas plasma such as oxygen or wet air has been developed. However, this development method takes advantage of the fact that the exposed and unexposed areas of the resist film are etched at different rates by gas/plasma, so if you develop too much, the development will stop. A problem has arisen in that the thickness of the subsequent resist film becomes extremely thin, which interferes with the subsequent etching process.

The present invention has been devised in view of these problems, and it is an object of the present invention to provide a dry developing device that accurately detects the completion of development.

The present invention will be described in detail below with reference to the drawings. 1st
3 to 3 are diagrams for explaining the process of developing a resist coated on a substrate using the developing device of the present invention, 1 is a substrate such as a mask or a semiconductor material, 2 is this This is a resist coated on a semiconductor substrate 1. Reference numeral 3 represents a developer tank, 4 and 4 represent parallel plate electrodes provided in the developer tank 3, and a substrate 1 to be developed is set between the electrodes 4 and 4. 5 is a high frequency power source that applies a high frequency voltage to the parallel plate electrodes 4, 4; 6 is a switch that supplies or cuts off the high frequency voltage supplied from this high frequency power source 5 to the parallel plate electrodes 4; 7 is a surface of the substrate 1; The ion detector is comprised of a mass spectrometer that determines the types of ions such as chromium ions and silicon ions emitted from the ion, and is configured to open the switch 6 upon detection of ions.

In such a developing device, a resist 2 coated on a substrate 1 is exposed in a pattern as shown in the first diagram, and this substrate 1 is exposed between parallel plate electrodes 4 in a developing tank 3.
After setting the plasma gas, e.g. Wet/Air
When the plasma gas is supplied, the switch 6 is closed, and plasma development is started, the resist 2 begins to be etched by this plasma gas. At this time, for example, in the case of a positive type resist 2, as shown in FIG. 2, the exposed areas exposed to the electron beam are etched faster than the unexposed areas. As the etching progresses further and the surface of the substrate 1 begins to appear in the exposed area as shown in FIG.
Silicon ions and the like are released from the surface of the substrate 1.
The ion detector 7 detects the release of these ions and measures the time, for example, 10 to 20 seconds, until the resist 2 in the exposed area is completely removed, and then the switch 6 is turned on.
The switch 6 is opened, the high frequency voltage applied to the parallel plate electrodes 4, 4 is cut off, and development is stopped.

Next, an experimental example of resist development performed using the developing device of the present invention will be described. A positive electron beam resist OEBR-100 (Tokyo Ohka) was applied to a thickness of 5000 Å on a chrome mask substrate, and after pre-baking at 80°C for 30 minutes, the exposure amount was 1×10 ^-4 covlomb/cm ²
Pattern exposure is performed using an electron beam of
Baking was performed for 10 minutes, followed by dry development. Wet air is used as the gas, and the pressure is
It was 0.1 Torr. The applied voltage was 1.0 KV, the frequency was 13.5 MHz, and the power was 100 W. Five minutes after the start of dry development, the chromium ion signal from the ion detector increased, so development was terminated. After completion of the process, a complete resist pattern was formed on the substrate, and the remaining resist film thickness was about 1000 Å.

As described above, the dry developing device of the present invention supplies plasma gas into the developer tank, applies a high frequency voltage between the parallel plates, and develops the resist on the substrate established between the parallel plates of the developer tank. When development progresses and the surface of the substrate appears, the ion detector detects ions emitted from the substrate, thereby identifying the completion of development, so it is possible to accurately know when development is complete. This makes it possible to form accurate resist patterns without causing over-etching or insufficient etching, and allows for finer micropatterning.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a substrate coated with resist.
2 and 3 are block diagrams of the dry developing device of the present invention. 1...Substrate, 2...Resist, 4, 4...Parallel plate electrode, 5...High frequency power supply, 6...Switch,
7...Ion detector.

Claims (1)

[Scope of utility model registration request] In a dry developing device that develops resist formed on a substrate using plasma discharge, a parallel plate electrode provided in a developer tank, a power source that supplies high frequency voltage to the parallel plate electrode, and a voltage emitted from the substrate surface are used. an ion detector for detecting ions, a substrate coated with resist is placed between the parallel plate electrodes, plasma gas is supplied into the developing tank, and a high frequency voltage is applied between the parallel plate electrodes. Plasma discharge is generated between both electrodes,
Resist development on the substrate surface is performed using the plasma, and when the development progresses and the substrate surface is exposed, the ions emitted from the substrate surface are detected by the ion detector to confirm the completion of the development process. A dry developing device characterized by identification.