JPS62127921A - Sample measuring instrument - Google Patents

Abstract

PURPOSE:To improve the operability by providing a keyboard for respective users. CONSTITUTION:The instrument is composed of a control panel to control the function only of a part of the computer and a full keyboard to control the function of most of the computer. The conditions of a refractive index, etc., are designated to a computer 5 by a control panel 6 and a pulling-out type full keyboard 7, the wavelength of a spectroscope 1 and the shifting quantity of a sample stage 2 are instructed and the command such as the measurement starting is executed. The control panel 6 is used for measuring under the conditions used ordinarily frequently, further, has a key to the necessary minimum so that an operator cannot execute the erroneous operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring a sample, particularly a sample measuring a film thickness of micrometer or less, such as an oxide film on silicon in a semiconductor manufacturing process.

Conventionally, this type of device has generally been a device in which various conditions are entered using a full keyboard and various commands are issued.

However, it is difficult for an operator without specialized knowledge to learn the functions of all the keys on a full keyboard, and there is also a risk of malfunction due to incorrect operation.

Therefore, it is impossible for an operator who repeatedly performs the same operation to operate a full keyboard as in the past.

The present invention improves operability by eliminating the drawbacks of the conventional technology and providing a keyboard for each user.

Before explaining the structure and operation of the present invention, the basic measurement principle will be explained using FIG. 1, and then as an example,
This will be explained in detail using FIGS. 2 to 5.

The basic measurement principle for film thickness calculation used in the present invention will be explained below with reference to FIG.

The refractive index of the medium is nl + n2 + 13 from the incident side
Let d be the film thickness to be measured now. The incident angle of each wavelength used (wavelength incidence in vacuum is 0) is 01. θ2.
Let it be θ3. The amplitude reflectance Y at this time is as follows.

[Reference+M, Born and E, Wolf,
“Pr1nciples of 0ptics”3
rdedition, PERGAMON PRESS
, p. 62] where Y12 is the Fresnel reflection coefficient at the boundary between media 1 and 2, Y23 is the Fresnel reflection coefficient at the boundary between media 2 and 3, and β is β=-Xname-n. 2 d cos θ
It is 2.

The quantity that can actually be measured is the reflection intensity, that is, R=lY12(
(usually called reflectance) and is as follows.

From equation (2), the film thickness d is as follows.

Here, N is an integer.

The reflectance R and d when changing the wavelength input 0 used are shown in Figure 1 (
b) and (C). Therefore, the film thickness d at each wavelength
By setting the average value dAV to 119 thickness, highly accurate measurement with good reproducibility can be performed.

FIG. 2.3 shows an embodiment of the present invention, which is an external view of the device and a block diagram of the system. In Figure 2.3, spectrometer 1
The fiber probe 3 illuminates the sample surface placed on the sample stage 2 with the separated light, and the fiber probe 3 receives the light reflected from the sample surface again. Convert to signal. The controller 4 controls the wavelength setting of the spectrometer 1 and the movement of the sample stage 2, converts the electric signal of the photoelectric conversion element of the spectrometer 1 into a digital signal, and confirms the position of the sample stage 2. The computer 5 controls the controller 4, receives the digital signal obtained from the controller 4, calculates the reflectance R, and calculates the reflectance R.
3) Calculate the film thickness d from the formula. The results are output to a character display such as a CRT 8, a floppy disk drive 9, or a printer 10. Using the operation panel 6 and the pull-out full keyboard 7, conditions such as the refractive index are specified to the computer 5, the wavelength of the spectrometer 1 and the amount of movement of the sample stage 2 are specified, and commands such as the start of measurement are issued. The operation panel 6 is used to perform measurements under commonly used conditions, and is equipped with the minimum number of keys necessary to prevent operators from making incorrect operations.For example, as shown in FIG.
When NDITION (7) +- is pressed, various conditions previously stored on the floppy disk are read by the floppy disk drive 9 in FIG. 2 and entered into the computer 5.

When you press LOAD l 2 of MEASUREMENT,
The sample on the north side of the sample stage is fixed by vacuum suction.

If you press it further, it becomes UN'''LODA and the sample is released.Press 5TART13 to start measurement.After the measurement is finished, press FILE14 of 0UTPUT to store the measured value on the floppy disk. Drive the floppy disk drive 9. To output the measured value to the printer 10, press PRINT15. To perform calculation processing on the measured value, for example, to calibrate it with another film thickness meter, press the CALC16 key. ,5TO
P key 17 is used to stop the measurement in an emergency; C0NT
Numeral 18 is a key for canceling the stoppage and continuing the operation, which can be operated by eight keys such as 0 and above. However, a full keyboard 7 is required to specifically input various conditions using alphanumeric characters, numbers, etc., and by providing both one and the other, it becomes possible to respond to each user's needs. The full keyboard 7 also has the key functions of the operation panel 6. Figure 5 shows the flow yard of the system. First step 19
When started, each device is turned on and initialized. The sample is fixed to the sample stage 2 by sample loading in step 20. The measurement condition input z1 is for entering conditions such as the refractive index of each layer, and is skipped if the same conditions are repeatedly used. Measurement starts with measurement start 22, and the sample moves to the first predetermined position, that is, the measurement position, and then stops. (
Step 23) Spectral reflectance is measured at that position in Step 24, and when the data is transmitted from the controller 4 to the computer 5, the sample stage 2 moves to the second predetermined position according to instructions from the controller 4 and stops. , measure the spectral reflectance. At the same time, the computer 5 calculates the film thickness at the first measurement position from the transmitted spectral reflectance data in step 25. In other words, the measurement time can be shortened by performing the first film thickness calculation and the second spectral reflectance measurement in parallel.The film thickness is calculated a predetermined number of times by repeating 0 or more, and then the step is totaled at all points. For example, calculate the average film thickness and standard deviation. The results are then displayed on the CRT in step 27 and output to the printer 10 or floppy disk 9. Further, in step 28, the film thickness data is calibrated using the next calculation, for example, a calibration curve with another film thickness measuring device, and is displayed on the CRT in step 29. When measuring the same sample again, return to the time before the measurement started, and when you want to change conditions such as the measurement position, return to the time before inputting the measurement conditions.

Next, the sample is removed by sample unloading in step 30. When measuring another sample again, return to the state before loading the sample.

The end of step 31 indicates the work of returning each device to its initial state and turning off each power source.

As described above, the present invention can provide a measuring device with extremely good operability, and can be applied not only to film thickness measurements but also to other measurements such as semiconductor circuit function tests.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the basic principle of determining film thickness from spectral reflectance used in the present invention. Figure 2 is an external view of an embodiment of the present invention, Figure 3 is a system block diagram of an embodiment of the present invention, Figure 4 is an operation panel diagram of an embodiment of the present invention, and Figure 5 is an implementation of the present invention. 1 is an example flowchart. 1 is a spectrometer, 2 is a sample stage, 3 is a fiber lobe, 4 is a controller, 5 is a computer, 6 is an operation panel, 7 is a full keyboard, and 8 to 10 are output devices.

Claims (2)

[Claims] (1) In an apparatus for measuring the film thickness of a sample, a sample stage, a computer that controls the sample stage, an operation panel that controls only a portion of the computer's functions, and a full keyboard that controls most of the computer's functions. A sample measuring device consisting of. (2) The sample measuring device according to claim 1, wherein the operation panel is arranged near the sample stage, and the full keyboard is arranged near the character display of the computer.