JPH04168715A - Forming device for photoresist pattern - Google Patents

Abstract

PURPOSE:To inhibit the dimensional change of a pattern while preventing positional displacement by mounting an exposure section forming the desired pattern to a photoresist film, a developing section, a size measuring section, a feedback mechanism section, etc. CONSTITUTION:A feedback section 6 is set up to a device control system 4 composed of a control section 7 controlling an exposure section 1, a control section 8 controlling a developing section 2, a control section 9 controlling a size measuring section 3 and a data processing section 5 data-processing the measured result of the section 3. The section 6 takes in the measured result from the measuring section 3 data-processed by the processing section 5, and transmits correction commands over the section 1 and the section 2 through each control section 7, 8. That is, a series of control system controlling the section 1, the section 2 and the section 3 is fitted, and the section 6 having a means storing each working condition data in the control system, a comparison means, etc., is mounted, thus inhibiting the dimensional change of a pattern while preventing positional displacement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoresist pattern forming apparatus for forming a desired pattern on a photoresist film by photolithography in the manufacturing process of semiconductor devices.

[Conventional technology]

Conventionally, this type of photoresist pattern forming apparatus has an exposure device that exposes a desired pattern on a photoresist film coated on a wafer, and a development device that develops the exposed photoresist film, each of which are independent. These devices were used as photoresist pattern forming devices by connecting them with a transport device.

Furthermore, the control devices for the exposure device and the developing device are separated, and the manufacturing conditions for each are set by the individual control devices.

Normally, the main control factor of exposure equipment is exposure energy, which greatly influences the dimension values of the pattern after subsequent processing in the developing equipment.Furthermore, the type of photoresist, wafer pretreatment, etc. , this exposure energy and the dimension values of the pattern showed a unique correlation.

On the other hand, as semiconductor devices become more highly integrated, the precision of misalignment for each pattern has come to be required to be as high as, for example, 0.1 to 0.2 μm.

Furthermore, the reality is that there are some elements in the control of the exposure device that cannot be checked until after processing has been performed by the developing device.

In this way, the exposure device and the development device are closely related, so for example, devices for measuring pattern dimensions include laser measurement devices, image processing measurement devices, and SEM measurement devices, but automatic dimension measurement devices As a measuring device, a laser measuring device has the best track record because it has good accuracy and can measure in a short time.

On the other hand, in order to maintain the quality of semiconductor devices, conventionally the dimensions of the photoresist pattern after development have been measured and the amount of deviation from the design dimension values has been managed. The amount of deviation is then corrected as a correction value in the exposure device, and the exposure device is controlled. In other words, the exposure device and the pattern dimension measuring device had a close relationship.

[Problem to be solved by the invention]

The conventional photoresist pattern forming apparatus described above has an exposure device and a developing device connected via a conveyance device. For this reason, each control factor has been fixed and processed. Therefore, even if the dimensions of the photoresist pattern vary or misalignment occurs, a large number of defective products will be produced until an operator inspects the pattern and adjusts the control factors.

In addition, in order to reduce the number of defective products, a pilot method is used in which multiple wafers are made into one lot, and the lot is passed through the exposure equipment and development equipment in advance, and then the finished product is inspected. During processing, each piece of equipment does not contribute to production, which not only lowers the operating rate but also extends the construction period itself.

An object of the present invention is to provide a photoresist pattern forming apparatus that eliminates such drawbacks.

[Means to solve the problem]

The photoresist pattern forming apparatus of the present invention includes an exposure section that forms a desired pattern on a photoresist film applied on a wafer surface, a development section that develops the exposed photoresist film, and a development section that develops the exposed photoresist film. a dimension measuring section that measures an arbitrary pattern dimension of the pattern; and a feedback mechanism that adjusts the dimension of the pattern to the alignment standard based on the correlation between the measured value of this pattern and the control factors of the exposure section and the development section. It consists of:

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the structure of an embodiment of the photoresist pattern forming apparatus of the present invention, and FIG. 2 is a block diagram showing the structure of the feedback section of FIG. 1. This photoresist pattern forming apparatus, as shown in FIG.
An exposure section 1 that exposes a pattern to a photoresist film on a wafer, a development section 2 that develops the exposed photoresist film, a dimension measurement section 3 that measures the dimensions of the formed pattern, and a device that controls each of these sections. It is composed of a control system 4.

The apparatus control system 4 also includes a control section 7 that controls the exposure section 1, a control section 8 that controls the development section 2, a control section 9 that controls the dimension measurement section 3, and the measurement results of the dimension measurement section 3. A data processing unit 5 processes the data, and the measurement results processed by the data processing unit 5 are taken in, and a correction command is given to the exposure device 1 and the developing unit 2 via their respective control units 7.8. It is composed of a feedback section 6.

On the other hand, as shown in FIG.
, misalignment correction amount storage section 1], development time correction amount storage section 12, and other storage section 15 to determine the correction amount; and the feedback command unit 1.
The data storage section 14 is configured to transmit data to each of an exposure control section 7, a development control section 8, and a dimension measurement control section 9 according to commands from the exposure control section 6.

Next, the operation of this photoresist pattern forming apparatus will be explained.

3(a) and 3(b) are flowcharts for explaining the operation of the photoresist pattern forming apparatus of FIG. 1. FIG. First, as shown in Figure 3(a), at [Start], the first
A wafer is placed on the stage of the exposure section 1 shown in the figure. next,
In [Read exposure information], the exposure control section 7 shown in FIG. 1 reads exposure information from the data storage section 14 shown in FIG.

Next, in [Read wafer information], it is checked whether the wafer is in the pre-exposure state in the other storage section 15 shown in FIG. Next, check [Is it consistent?] ], the exposure section 1 stores other information such as whether it is OK to carry out the exposure or not.
be consistent with. For example, it is checked whether the wafer is in a pre-exposure state, and whether the read exposure conditions match the product name, process name, number of wafers, etc., with the read product.

Next, once the alignment is achieved, click [Correction corrected?] ] So, N.

If so, just expose. If YES, data is exchanged between the data comparison section 13, the exposure amount correction amount storage section 10, and the misalignment correction amount storage section 11, and the exposure amount and misalignment correction amount are determined; Data storage section 1
4 as new exposure information, and the exposure control section 7.
Change the exposure conditions before sending. Next, in [Exposure], the control unit 7 instructs the exposure unit 1 to perform exposure under the changed conditions.

Next, when the exposure is completed, the development information is read from the development control section 8 or the data storage section 4 in [read development information]. Next, check [Is it consistent?] ], the storage section 15 and the data comparison section 13 are used to determine whether or not the development section 2 may perform the development. For example, the state of the wafer before development, the product whose development conditions have been read, the product name and process name,
Check whether the numbers match. Next, if the alignment is correct, check [Corrected?] ], the development time correction amount storage section]
2 and the data comparison section 13 to determine the amount of correction for the development time, store new image information in the data storage section 14, and change the conditions to the development control section 8.

Next, in [Developing], the developing unit 2
develops the photoresist film on the wafer.

Next, when development is completed, [read the dimension measurement information]
Then, the dimension measurement information is read by the dimension measurement control section 9. Next, in [read wafer information], the control section 9 confirms that the wafer is in the developing section. Next, check [Is it consistent?] ], the other information is retrieved from the storage section, and the dimension measuring section 3 makes a decision as to whether or not to proceed with the dimension measurement. For example, the wafer is in a state before dimension measurement, and it is checked whether the read dimension measurement conditions match the product name, process name, number of wafers, etc., with the read product. Next, if the alignment is achieved, measure the dimensions using [Measure dimensions].

Here, this [measurement of dimensions] will be explained using a specific example.

FIG. 4 is a diagram showing a pattern drawn in one area of the wafer and a laser output waveform in this pattern. In this dimension measurement, first, as shown in FIG. 4, a laser beam is scanned in the X and Y directions for the patterns 17 and 18 in one area of the wafer. Pulse waveforms are obtained at positions X1 to x4 and positions X1 to x4, which are the boundaries between the respective patterns.The data of the pulses obtained here are processed by the data processing section 5, for example, from X2 to XI or y2. -yl
These calculations are performed to obtain each dimension of the photoresist pattern, which is sent to the data comparison section 13. Furthermore, assuming that the misalignment amount is the design value (X, Y), the respective misalignment amounts (ΔX, Δy> are calculated by the arithmetic formula using the aforementioned data Xl to x4 and X1 to x4 in the data processing unit 5, Δx= (X (X4 +x3 x2 Xl)
) / 2Δy= (Y-(y4+y3-y2-, Y
It is calculated by l ))/2. Next, in [reading the dimension measurement result information], these aggregated data are sent to the data comparison section 13.

Next, in [calculating the correction amount], the data comparison unit 13
These sent dimension measurement information and exposure amount correction amount storage unit 1
0, the data in the development time correction amount storage section 12 and the misalignment correction amount storage section 11 are compared, and the respective correction amounts are set. The next wafer is processed taking into consideration the correction amount.

FIG. 5 is a plan view of a wafer for explaining the operation of the photoresist pattern forming apparatus of FIG. 1. Also, −
Misalignment correction of exposure shots for each region is, for example, as shown in FIG. 5, by correcting the direction and amount of correction from arbitrary coordinates of each region as one misalignment amount correction vector.

Next, the operation when there is no matching before starting the operation in each step will be explained. First, the operation before the exposure operation in FIG. 3(a) (does it match?) is N.

If so, as shown in FIG. 3(b), (Is the number of mismatches greater than or equal to the specified number of times?), the number of mismatches when comparing the data stored in the other storage unit 15 with the input data. Count. If the number of times exceeds and the answer is YES, (sends work error information to the display unit), the data comparison unit 13
An error signal is then sent to the exposure control section 7. Next, in (Stop the device), instruct the device to stop operation 1 to stop the device.

If the number of times is less than the specified number, that is, if the answer is NO, the data comparison unit 13 sends a wafer exchange signal to the control unit 7 in (Send wafer error information to the display unit). Next, in (wafer unloading), the wafer is taken out from the exposure section 1. Next, in (Bringing in a new wafer), a regular wafer is set in the exposure section 1.

Further, in the development operation and the dimension measurement operation, if there is a mismatch, the entire apparatus is stopped or the wafer is newly set and restarted from the initial start.

[Effects of the Invention] As explained above, the present invention also includes a series of control systems that control the exposure section, the development section, and the dimension measurement section, and this control system includes:
By providing a storage means for storing each piece of work condition data, and a feedback mechanism that constantly updates the work condition data by comparing the work condition data in this storage means with the new work condition data and performing comparison processing, the pattern can be improved. This has the effect of providing a photoresist pattern forming apparatus that can suppress dimensional variations and prevent misalignment.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the photoresist pattern forming apparatus of the present invention, FIG. 2 is a block diagram showing the configuration of the feedback section in FIG. 1, and FIGS. 3(a) and (b). 1 is a flowchart for explaining the operation of the photoresist pattern forming apparatus shown in FIG. 1, FIG. 4 is a diagram showing a pattern drawn on one area of the wafer and the laser output waveform in this pattern, and FIG. FIG. 2 is a plan view of a wafer for explaining the operation of the photoresist pattern forming apparatus of FIG. DESCRIPTION OF SYMBOLS 1... Exposure section, 2... Developing section, 3... Dimension measuring section, 4... Apparatus control system, 5... Data processing section, 6...
- Feedback section, 7.8.9 - Control section, 10...
・Exposure amount correction amount storage unit, 11... - Misalignment correction amount storage unit, 12... Development time correction amount storage unit, 13... Data comparison unit, 14... Data storage unit, 15...・Feedback command section, 17.18...-pattern, 1・
... Wafer, 20... Misalignment amount correction vector. (b)

Claims (1)

[Claims] An exposure section that forms a desired pattern on a photoresist film applied on a wafer surface, a development section that develops the exposed photoresist film, and a dimension that measures arbitrary pattern dimensions of the developed pattern. A photoresist comprising: a measuring section; and a feedback mechanism for adjusting the dimensions and alignment standards of the pattern based on the correlation between the measured values of the pattern and control factors of the exposing section and the developing section. Pattern forming device.