JPH0133942B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dimension measuring method for electrically measuring the dimensions of contact holes or through holes in semiconductor integrated circuit devices.

BACKGROUND OF THE INVENTION As semiconductor integrated circuits become smaller and smaller, accurate measurement of device dimensions has become essential for accurately understanding device characteristics and determining manufacturing conditions.

Conventional methods for measuring contact hole dimensions include microscopic observation or scanning electron microscopy. Since these methods cannot be automated, the number of measurements is small, and accurate manufacturing status cannot be determined.

In other words, microscopic observation is inaccurate after the manufacturing process is completed because the device is covered with several types of interlayer films, and scanning electron microscopy allows accurate observation after the manufacturing process, but it contaminates the device. In some cases, it may not be possible to observe it without destroying it.

Problems to be Solved by the Invention As described above, in the conventional method, accurate dimensions of contact holes or through holes can be determined in large quantities in a short time, and moreover, after the manufacturing process is completed, automatically without destroying the device. It is impossible to measure.

An object of the present invention is to make it possible to electrically measure the dimensions of contact holes or through holes in semiconductor integrated circuit devices, and to automate the dimension measurements.

Means for Solving the Problems The configuration of the present invention includes a resistor formed of a diffusion layer or a wiring layer having contact holes or through holes at both ends, and a resistor having the same shape and structure as the resistor. It consists of another resistor with a contact hole or through hole arranged for the purpose of measurement, and an element for electrically deriving the layer resistance and width of a diffusion layer or wiring layer arranged in the vicinity.

Function: With this configuration, the dimensions of the contact hole or through hole can be derived from three types of resistance values between the contact hole or through hole, the layer resistance of the wiring layer or diffusion layer, and the width of the resistor.

Embodiment FIGS. 1, 2, and 3 each show a plan view of an embodiment.

FIG. 1 shows a diffusion layer or wiring layer 5 having a width W and contacting parts of electrodes 1 and 2 with contact parts 3 and 4, and having a distance L ₁ between both contact parts 3 and 4. The figure shows a resistor formed by electrodes 1 and 2, which are connected to contact parts 3 and 2, respectively.
4 and is a voltage measurement terminal. electrode 6,
Reference numeral 7 denotes an electrode that has contact portions 8 and 9, respectively, and contacts the diffusion layer or the wiring layer 5 at the rear extensions of the contacts 3 and 4 of the electrodes 1 and 2, and is a current application terminal. When a constant current I ₁ is passed between electrodes 6 and 7, and the voltage of electrodes 1 and 2 is V ₁ , the resistance R ₁ between contact holes 3 and 4 is R ₁ = V ₁ /I ₁ = R _S ×L1 /W ......(1) It is expressed as. Here, R _S is the layer resistance of the diffusion layer or wiring layer 5.

FIG. 2 shows another resistor, in which a resistor is formed of a diffusion layer or a wiring layer 20 having a width W and a distance L ₂ between contact parts 16 and 17, and a resistor having a width W and a contact part 17. , 18 distance L3
The contact portion 1 is connected in series with a resistor formed of a diffusion layer or a wiring layer 20 having
The distance between 6 and 18 is L1, which is the same as the resistor shown in the first diagram.
It is. The dimensions of the contact portion 17 are CW.
Electrode 1 connected to contact parts 15 and 19
3 and 14 are constant current application terminals.

The applied current between electrodes 13 and 14 is I2, and electrode 1
If the voltage between electrodes 0 and 11 is V2, and the voltage between electrodes 11 and 12 is V3, then the resistance of each resistor with dimensions L2 and L3 is
R ₂ R ₃ is expressed as R2=V2/I2=R _S ×L2/W (2) R3=V3/I2=R _S ×L3/W (3).

Here, R _S is the layer resistance of the diffusion layer or wiring layer 20, and is the same as the layer resistance of the resistor shown in FIG.

Also, as shown in Figure 2, L1=L2+CW+L3...(4) It is.

From equations (1), (2), and (3), L1=W×R1/R _S ……(5) L2=W×R2/R _S ……(6) L3=W×R3/R _S ……( 7) Then, the dimension CW of the contact hole or through hole that should be determined by equations (5), (6), (7), and (4) is CW = L1- (L2 + L3) = W/R _S × (R1- R2−R3) ...(8), and if the layer resistance R _S and width W of the diffusion layer or wiring layer 5 (or 20) are known, CW can be found.

The principle of the present invention for determining the dimensions of a contact hole or a through hole using the resistance value of a resistor has been explained above using examples.

By the way, FIG. 3 shows a Van der Pauw pattern and a bridge pattern for electrically measuring the layer resistance R _S and width W of the diffusion layer or wiring layer 35, which have been conventionally used.
der Pauw pattern electrodes 21, 22, 24, 2
5 is connected to the contact portions 28, 29, 31, and 32, and when an applied current _IRS is applied to the electrodes 21 and 22, and the voltage between the electrodes 24 and 25 is _VRS , the layer resistance of the diffusion layer or wiring layer 35 is R _S can be expressed as R _S = π --- 1n2 ‖ (4.532) × (V _RS /I _RS ) ...(9).

When the applied current I _R is applied to the electrodes 22 and 23, and the voltage between the electrodes 26 and 27 is V _R , the width W of the diffusion layer or wiring layer 35 is W=R _S ×L4×I _R /V _R ...( 10) Let it be expressed as Here, L4 is the contact part 33 and 3
It is the distance between 4.

As above, if the width W and layer resistance R _S of the diffusion layer or wiring layer are determined from equations (9) and (10), then the resistance values R1, R2, and R3 of resistors 1, 2, and 3 are calculated from equation (8). From this, the dimension CW of the desired contact hole or through hole can be found.

Effects of the Invention According to the present invention, a target contact hole can be formed based on the resistance values of three types of resistors having the same width formed in a diffusion layer or a wiring layer, and the values of the widths of these resistors and the layer resistance value. Alternatively, the value of the through hole can be derived electrically and the measurement can be automated.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are plan views of a resistor for dimension measurement used in carrying out the present invention. 1, 2, 6, 7... electrode, 3, 4, 8, 9...
Contact portion, 5... Diffusion layer or wiring layer forming a resistor.

Claims (1)

[Claims] 1. The same shape is placed on both ends of the diffusion layer or wiring layer, which has a certain width and an appropriate length that is sufficiently longer than that.
a first diffused resistor or wiring resistor in which contact holes of the same size are arranged a predetermined distance apart;
A contact hole having the same shape and dimensions as the contact hole is formed at a predetermined distance from the first diffusion resistor or wiring resistor on the same kind of diffusion layer or wiring layer having the same shape and dimensions as the diffusion layer or wiring layer. A contact hole having the same shape as each of the contact holes is arranged near the middle thereof, and a second diffused resistor or a wiring resistor formed between the contact holes and a third A dimension measuring method characterized in that the dimensions of a contact hole or a through hole 4 are derived from the resistance values of a total of three types of resistors: a diffused resistor or a wiring resistor.