JPH02146545A - Automatic developing device - Google Patents

Abstract

PURPOSE:To improve the size accuracy when substrates to be developed which have different pieces of mask information are processed at a time by reading mask information marked on an end surface of a substrate to be developed before dipping the substrate in a developing tank and determining the best development conditions according to the mask information. CONSTITUTION:On a set stage, an image sensor 6 reads the mask information 7 on the substrate 1 before development. The read mask information is discriminated by a pattern recognition part 30 and sent out to a development condition determining means 40. The best development conditions which are obtained by an experiment for the kinds of a mask material and resist and various combinations of resist coating lots are put in a table and stored in the memory in the development condition determining means 40. The development condition determining means 40 determines the best development conditions according to the mask information sent through a pattern recognition part 30. Consequently, the size accuracy is excellent and development with small variance is performed automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to an automatic developing apparatus, and is particularly used for resist developing processing of tools or glass masks.

(Prior Art) In order to pattern a resist coated on a wafer and a glass substrate for a mask, a development step is required after exposure. In recent years, the density of semiconductor devices has increased, and pattern dimensions are required to have extremely high precision. Generally, the pattern width is greatly affected by the development time, so it is necessary to appropriately control it.

For this reason, the appropriate end point of development can be determined by immersing a reference electrode and a second electrode made of a conductor coated with resist in a developer and observing the current flowing between the two electrodes during immersion development. An automatic developing device with a
25667).

(Problem to be solved by the invention) However, when processing multiple substrates with different mask information, that is, mask material, resist type, and resist application lot (change over time) at the same time, the above control is not performed. However, there were differences in the progress of development depending on the substrate to be developed, and the dimensional accuracy between patterns after development was not necessarily good as shown in FIG. In other words, the difference from the design dimensions varies considerably.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an automatic developing device that can improve dimensional accuracy even when processing multiple substrates to be developed with different mask information at once. shall be.

[Structure of the invention]

(Means for Solving the Problems) An automatic developing device according to the present invention includes a developer tank filled with a developer in which a resist-coated substrate to be developed is immersed, a first electrode and a substrate immersed in the developer tank, and a first electrode and a substrate immersed in the developer tank. A second electrode coated with resist and immersed in a developing tank, and mask information pre-marked on the end surface of the substrate to be developed,
A reading means that reads the substrate to be developed before it is immersed in the developing tank, a developing condition determining means that determines the optimum developing condition based on the mask information read by the reading means, and between the first and second electrodes. The present invention is characterized by comprising a development end point determination circuit that detects the current flowing during development and determines the development end point of the substrate to be developed based on the detected current value and the determined optimal development conditions.

(Function) According to the automatic developing device of the present invention configured as described above,
Mask information pre-marked on the end surface of the substrate to be developed is read by a reading means before the substrate is immersed in the developing tank. Then, the optimum developing conditions are determined by the developing condition determining means based on the read mask information. Next, when the substrate to be developed is immersed in the developer tank, development starts. At this time, the current flowing between the first and second electrodes is detected by a development end point determination circuit, and the development end point of the substrate to be developed is determined based on this detected current value and the above-mentioned optimal development conditions.

As a result, even when processing multiple substrates with different mask information at once, the optimal development conditions for each substrate are determined, and the development of the substrates is performed based on the determined development conditions. By doing so, it is possible to improve the dimensional accuracy.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view showing a schematic configuration of an automatic developing device according to the present invention, and FIG. 2 is a plan view thereof. According to these, the part shown on the left is a set stage for setting the board,
The part shown on the right side is a developing stage for performing development, and a substrate 1 made of a wafer or a glass plate is held by a conveying arm 3 on the set stage and moved to the developing stage. That is, the notches 3a that engage with the corners of the substrate 1 are formed inwardly at the tips of the two transfer arms 3, and the transfer arms 3 move inward so as to sandwich the substrate 1 between them. The substrate 1 is gripped and conveyed as it is to the development chamber 10. The transportation arm 3 can be stably moved by, for example, rotating the screw shaft 4. Furthermore, a chrome electrode 16 is attached to a notch 3a at the tip of the transport arm 3.

Above the set stage, an illumination lamp 5 and an image sensor 6 such as a CCD line sensor are provided, and as will be described later, these detect mask information pre-marked on the substrate, that is, the mask material, the type of resist, and the resist. This is for reading information 7 consisting of the application port and the opening. The image sensor 6 is controlled by a sensor controller 20, and the read output is manually input to a pattern recognition section 30. The output of the pattern recognition section 30 is input to the development condition determining means 40.

A developer tank 11 is provided in the developer chamber 10.
In this developer tank 11, the substrate to be developed is rotated by a motor 15 for rotating the substrate.
Rotated by A developer supply nozzle 12 for supplying a developer is provided above the developer tank 11, and the developer filled in the developer tank 11 is discharged from a discharge port 13 of the developer chamber 10. There is. A reference electrode 17 is arranged along the inner peripheral surface of the bottom surface of the developer tank 11 . This reference electrode 17 and the aforementioned chromium electrode 16 are connected to a development end point determination circuit 50. Further, the output of the development condition determining means 40 is also input to the development end point determination circuit 50. A spray nozzle 14 is provided on the inner wall of the developing chamber 10, from which a rinsing liquid and hot air for drying are supplied to the substrate after development.

Next, the operation of such an automatic developing device is shown in Figures 1 to 3.
This will be explained with reference to the figures.

First, on the set stage, the mask information 7 on the substrate 1 before development is read by the image sensor 6. This read mask information 7 is identified by the pattern recognition section 30 and sent to the development condition determining means 40. On the other hand, optimal development conditions obtained through experiments for various combinations of mask materials, resist types, and resist application lots are compiled into a table and stored in a memory within the development condition determining means 40. And pattern recognition section 3
Based on the mask information sent through 0, optimal development conditions are determined by the development condition determining means 40.

On the other hand, after the mask information is read by the image sensor 6, the substrate 1 coated with the resist 2 to be developed and the chrome electrode 16 coated with the resist together with this substrate are transported into the development chamber 10 by the transport arm 3. and is immersed in a developer in a developer tank 11. As a result, development is performed, and the chromium electrode 16 and the reference electrode 1
The current flowing between 7 and 7 changes as the development time elapses as shown in FIG. That is, the current flowing through the developer reaches its maximum value at time t, and the sign of the differential coefficient is reversed. The actual optimum development time is longer than the time at the inflection point.
The total time of time ta and tb is the optimum development time. The optimum development condition determined by the developing condition determining means 40 is the ratio γ-tb/l of time t and ta shown in FIG.

On the other hand, the current flowing between the chromium electrode 16 and the reference electrode 17 is monitored by a development end point determination circuit 50.
For example, the maximum value as a singular point is detected by detecting the sign reversal of the differential coefficient of the current value. When such a singular point is discovered, the optimum development condition is determined by multiplying the actual development time t until the current reaches its maximum value by the optimum development condition, that is, the ratio γ, determined by the development condition determining means 40. The additional development time t is determined by the development end point determination circuit 50.
is required. Then, the substrate 1 to be subjected to phenomenon is pulled up after the determined optimum additional development time, and the development is completed.

The result of the development carried out in this manner is shown in FIG. According to this graph, the difference from the design dimensions is mostly ±0.
05 μm, indicating that extremely accurate development can be obtained.

In addition, as mask information, a marker as shown in Fig. 6 (
The pattern or code) may be formed in advance on the substrate 1 to be developed (resist lower layer), or may be formed on the resist upper layer using a laser.

〔Effect of the invention〕

As described in detail above, according to the present invention, even when processing a plurality of target substrates with different mask information at the same time, optimal development conditions are determined according to each individual target substrate, and the determined development conditions are By developing the substrate to be developed based on the conditions, it is possible to automatically perform development with good dimensional accuracy and little variation.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a schematic configuration of an automatic developing device according to the present invention, FIG. 2 is a plan view thereof, and FIG. Figure 4 is a graph showing variations in dimensional accuracy after development using the present invention, Figure 5 is a graph showing variations in dimensional accuracy when developed using conventional technology, and Figure 6 is a graph showing variations in dimensional accuracy after development using the present invention. FIG. 3 is a diagram showing a specific example of mask information to be processed. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Resist, 3... Transfer arm, 6... Image sensor, 7... Identification symbol, 10
...Development chamber, 11...Developer tank, 14...Spray nozzle, 15...Substrate rotation motor, 16...
- chrome electrode, 17... reference electrode, 20... sensor controller, 30... pattern recognition section, 40...
Development condition determining means, 50...Development end point determination circuit. trap

Claims (1)

[Scope of Claims] A developing tank filled with a developer in which a resist-coated substrate is immersed, a first electrode immersed in the developing tank, and a resist-coated substrate immersed in the developing tank together with a first electrode and the substrate. a second electrode that reads mask information marked in advance on an end surface of the substrate to be developed, before the substrate to be developed is immersed in the developer tank; and mask information read by the reading device. a developing condition determining means for determining an optimal developing condition based on the above; and a developing condition determining means for detecting a current flowing between the first and second electrodes during development, and based on the detected current value and the determined optimal developing condition. An automatic developing apparatus comprising: a development end point determination circuit that determines a development end point of the substrate to be developed.