JPS5839025A - Measuring method for characteristics of semiconductor device - Google Patents

Abstract

PURPOSE:To accurately measure the characteristics of an element for confirming the contacting resistance formed at a semiconductor wafer by measuring the element, thereby detecting the contacting state with the element of a contacting probe. CONSTITUTION:When elements 11, 11... are formed by impurity selective diffusion in a semiconductor wafer 10, elements 12, 12... for confirming the contacting resistances are formed at a plurality of positions. At the time of measuring the characteristics, a probe card 16 is lowered by the prescribed distance to contact the contacting probes 17, 17... led from the card 16 with the electrodes 18, 18... of the elements 11, 11.... Thus, the characteristics are measured, thereby discriminating the propriety. When the measurements are advanced and the card 16 is moved onto the element 12, the resistance value between the electrodes 15, 15 is measured, thereby discriminating the propriety of the contacting state of the probes 17, 17. As a result of the measurements, when the resistance value is discriminated as proper, the measurement is continued, and the measurement of the characteristics of the general element 11 is then performed. When discriminated as improper, the measurement is stopped, and the height of the probes 17, 17 are adjusted to place the resistance value within the prescribed range, and the measurement of the characteristics of the other general element 11 is performed in the adjusted state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the characteristics of a semiconductor device, and particularly to a method for accurately measuring individual semiconductor elements formed on a semiconductor wafer. As shown in the figure, a large number of independent large semiconductor elements (phantoms) are formed in a network shape on a single silicon semiconductor wafer +1+ through various impurity selective diffusion processes, ohmic processes, etc., and each of these elements (phantoms) is The semiconductor element (hereinafter simply referred to as an element) (by selective diffusion of impurities) is formed into an integrated circuit including transistors, diodes, resistors, etc., as shown in Figure 3 on the surface. to each IJI
A large number of electrodes (easy) corresponding to K are formed.

The above semiconductor device is made of a semiconductor wafer (1
) The characteristics of each element (K) are measured to determine its quality. As shown in the figure, the boop card (4
) to the same number of contact probes (1) as the electrodes of element (2) -.
When measuring, using a measuring device (-1) with which the contact probe (1 strip) is guided downward,
The characteristics are measured by applying a current to - and passing a current through it.The results of the measurement show that if it is a good product, it is t''*KL, and if it is a defective product, the element is #). Even if the semiconductor wafer (1) is separated by appropriately marking the surface, there is no way to avoid supplying defective products to the mounting process.

However, the probe card (4) is designed to move up and down at a predetermined constant stroke in order to carry out self-excited measurements, and it is sufficient if the semiconductor wafer (1) is formed flat. The semiconductor wafer il+ has irregularities in various parts due to thermal shadow change during selective diffusion of impurities. Therefore, the surface position of the semiconductor wafer ill differs from the amount of descent of the glove card (4).
If the contact state of... is unstable, if the amount of descent is adjusted to match the convex part of 4 & conductor quafer (11), the contact pressure of the contact probe Ill iIl... will be reduced when measuring in the concave part. In some cases, the contact was low, or in extreme cases, there was no contact at all, making it impossible to measure accurately, resulting in many elements being judged as unnecessary. In this case, the contact pressure of the contact probe [51161...] became too high at the convex portion, and the semiconductor wafer (1) was often damaged, resulting in poor yield.In addition, the yield was poor.
<4) For some reason, the probe did not descend the prescribed stroke, and (9) due to wear of the contact probe illumination, it was difficult to make accurate measurements due to insufficient contact.

This invention has been made to address the above-mentioned problems of the conventional characteristic measuring method and to eliminate these problems by forming elements for contact paper K11lE having a constant resistance value at predetermined locations on a semiconductor wafer, Sorry! ! Measure by touching the contact probe of the glove card to the electrode of the E element, use the measured value to determine whether the contact state of the contact probe is good or bad, and if it is a storm, measure other elements under the same condition. If not, the measurement is stopped, the contact probe is set in the correct state, and another measurement is performed. ◎ Hereinafter, embodiments of this invention will be explained with reference to the drawings. .

As shown in FIG. 4, the present invention involves forming elements 1 (11) having a large number of transistors, diodes, resistors, etc. on a semiconductor wafer by selective diffusion of impurities.
A cable ama field for contact resistance confirmation is formed at a plurality of locations. For example, as shown in FIG. 6, the electrolytic element A is formed by selectively diffusing summer type impurities over the entire surface of the element in a semiconductor wafer (PfIIi substrate) to form a resistive layer 91 having a predetermined resistance value. , an insulating layer a (and electrodes a and Q are formed on its surface. This element 91 is a semiconductor wafer ^(
◎ On the other hand, the characteristics of the general cable 01 (11... Contact resistance confirmation element for measurement -m-
A programmer is provided to measure the resistance value.

When measuring the characteristics, as shown in Fig. 1, the probe I is lowered by a certain amount according to the predetermined procedure, and the contact probe a' guided out from the probe n (1
7) -- is brought into contact with the electrode I4 -- of the element (11), its characteristics are measured, and whether it is good or bad is determined. If the measurement result is good, measure the 11th-order element (11); if the measurement result is bad, measure the element 111) by appropriate means.
Mark the defective surface on the surface and move on to the next measurement.

As the measurement progresses and the probe card 9 o'clock reaches the end of the element for contact resistance confirmation, one contact probe is again brought into contact with the electrode Q4a of the contact resistance confirmation element (Ikon) as shown in Figure 1. Let me,
Measure the resistance value R between both electrodes (11), and connect the contact probe ■fist η
Determine whether the contact status is ^/defective/Rima) Both electrodes 019
If the measured resistance value between 4 and 9 has been set in advance and is between the lower limit x1 and the upper limit of the nine limit resistance @1'm (R1≦R1&1m), then the contact probe #Gin/Bori electrode-HK is The contact state is determined to be stormy, and if it is outside the above range, the contact state is determined to be poor. It is expressed as the sum (1°1-100.times.) of the value l- and the contact resistance value 1o between the electrode 0@- and the contact probe H). In this case, the resistance value of the resistance layer 11! −
shows a one-shot value, so the resistance value is 1&fa! Touch Jl! It is determined by the resistance value Xa, and the contact resistance value R (fH
:The resistance value changes as the resistance changes. Therefore, when the resistance value m is within the range of the marginal resistance value, the contact resistance value 11e is normal and T
oc, the contact state of the contact probes I and η is determined to be good. In addition, if the resistance value R is outside the range, for example, if it is smaller than the lower limit Rz of the limit resistance value, the contact resistance value RC is small and the contact probe μη
The contact pressure of aη is low and becomes defective, and conversely, if it is larger than the upper limit R1, the contact resistance value Rc is large and the contact probe 07)I
The contact pressure of η is high and it becomes defective.

As a result of the above contact resistance measurement, if the resistance value R is determined to be good, continue the 11 measurements and move on to measuring the characteristics of the general element (river).On the contrary, if it is determined to be defective, the measurement Stop the contact probe o7 so that the resistance value is within range H.
) Adjust the height of eη, etc., and move on to measuring the characteristics of other general elements (lυ) in the adjusted state.

As mentioned above, when measuring the characteristics of a medium conductor wire, each element (
Measure the characteristics of 50aυ..., form mK on the semiconductor wafer, and form a contact resistance confirmation element @#as-
・Measures the contact state of the contact probe αη- to the element for characteristic measurement, and corrects the contact state correctly, so that accurate characteristic measurements can be made at all times. - Since these marks are scattered at various parts of the conductor, it is possible that various parts of the semiconductor wafer (LO) may be uneven and may fall, or for some reason the probe card (II) may not have descended correctly. Even if the contact probe α40η is deformed due to wear, it can be immediately detected and adjusted, and accurate measurements can be made over the entire semiconductor wafer. The resistance confirmation element has been described in the case where a resistance layer value field is formed by impurity diffusion within a semiconductor wafer, but it is also possible to form a metal layer on the surface of a semiconductor wafer as shown in the 8th FA. An element using this as a resistance layer may also be used.

As explained above, according to the present invention, the contact state of the contact probe with the element is detected by measuring the contact resistance confirmation element formed at a suitable location on the semiconductor wafer, and thereby the contact state of the contact probe with the element is constantly detected. It can be adjusted to the correct state, and even if there are unevenness in various parts of the semiconductor wafer, if the amount of descent of the probe card is different, or even if the contact probe is worn out, it can be avoided. Therefore, the characteristics of the device can be accurately measured without being affected by the noise, and the reliability and yield of the product are improved.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a general example of a semiconductor wafer on which elements are formed, and Fig. #g3 shows the elements formed on the semiconductor wafer.
FIG. 8 is an enlarged cross-sectional view showing an example of the characteristics of the device; FIG. 4 is a plan view showing the formed state of the device of the conductor to which the present invention is applied; Part bv
A is an enlarged cross-sectional W diagram showing an example of a contact resistance confirmation element, #g
Figure 6 is an enlarged cross-sectional view showing the characteristic measurement of a normal element, Figure 7 is an enlarged cross-sectional view showing the measurement of a contact resistance checking element, and Figure 8 is an enlarged view showing another example of the contact resistance checking element. A cross-sectional view of 〇-...semiconductor wafer, [phantom...semiconductor element, -]
- Element for contact resistance confirmation, - Resistance layer, ■... Insulating layer,
α gift...electrode, -...boob card, η
... Contact probe. Figure 1 Figure 2 WJ Nib Figure 8

Claims (1)

[Claims] (1) Form contact resistance confirmation elements having specific resistance values at multiple locations on a semiconductor wafer on which a large number of semiconductor elements are formed, and contact the surface electrode of the contact resistance confirmation element with a plate card. The characteristics of the semiconductor element are measured while the contact state of the contact probe with the element is detected by K when the probe is brought into contact and whether the resistance value is within a preset limit resistance range. A method for measuring characteristics of a semiconductor device, characterized in that: