KR19990005477A - Wafer Electrical Characteristics Measuring Apparatus and Measuring Method - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Wafer Electrical Characteristics Measuring Apparatus and Measuring Method

2. The technical problem to be solved by the invention

It aims to provide an electrical property measuring device and measuring method in semiconductor devices that can perform efficient measurement work by reducing measurement time by quickly and effectively responding to various measurement point measurement, various size device measurement, and various measurement items.

3. Summary of Solution to Invention

Chuck means for seating the wafer to ground; Probe means having a first probe portion connected to a positive (+) power supply line and a second probe portion connected to a negative (-) power supply line and grounded, each probe contacting a plurality of measurement points of the wafer; And measuring means for detecting an electrical characteristic of the line between each measuring point contacted by the measuring pin of the probe means and an electrical characteristic between the first probe portion and the chuck means.

4. Important uses of the invention

It is applied to a memory test that measures electrical characteristics by measuring a DC parameter of a wafer, and thus has an economic effect of reducing a measurement time and a wide range of measurement items.

Description

Wafer Electrical Characteristics Measuring Apparatus and Measuring Method

The present invention relates to an apparatus for measuring electrical characteristics of a wafer and a measuring method using the apparatus, and more particularly, to a measuring apparatus and a measurement prevention method capable of rapidly measuring a DC-parameter at several points or simultaneously during a characteristic test. .

In general, various tests are used to inspect semiconductor devices in a semiconductor manufacturing process. Among them, there is a characteristic test, which relates to the present invention, which is a method of checking the characteristics of a device by measuring AC or DC parameters at a wafer or package level. The apparatus and method for examining the characteristics will be mainly described.

In the prior art, auto probing equipment was mainly used as a device for measuring the DC parameters in the device. The configuration and DC-parameter measurement method of the device will be described briefly with reference to FIG. 1. The device is a device in which an element is inspected by using a probe card 11, as shown. , A chuck 13 provided on an upper portion of the device main body 1, on which a pad (that is, a device under test (DUT) 12) is seated, and an upper portion of the chuck 13 surrounding the pad 12. Probe card 11 provided in the, and one end is connected to the probe card 11, and the other end comprises a probe 14 for performing contact with the measuring point on the pad 12 during the measurement operation, the probe A positive power supply line is connected to the probe 14 in the card 11, and a ground power supply line is applied to the chuck 13.

Thus, in order to measure the DC parameter, the probe 14 is fixed at a predetermined position on the probe card 11, and when its end moves to a measuring point on the pad 12 to be measured, the electrostatic source line Between the probe 14 of the probe card 11, the measuring point on the pad 12, and the chuck 13 in contact with the lower surface of the pad 12 are energized and the measuring unit 2 is energized. By checking the conductivity of the applied current, for example, a wafer level test to check the contact between the system head and the dirt board, the probe card and the dirt board, and the contact between the system head and the dirt board, the package and the dirt board. It checks the electrical connection between pads and external peripherals such as package level tests. Also, it performs other various measurement items such as leakage test and power consumption measurement of devices. It is good.

However, in the DC-parameter measurement method in the above-mentioned conventional electrical characterization equipment, the probe 14 and the grounded chuck (1) in which one probe 14 whose position is fixed only touch one measurement point on the pad ( 13) Since it was a single configuration, it was necessary to adjust the pads by moving the pads again so that the probe 14 could be touched to the required new measuring point when a measurement was required that was different from the previous measuring point. Accordingly, when measurement at several points is required, for example, in the case of the constant current stress time (CCST) item among electrical parameters, it takes about 300 seconds at one measurement point, and thus the above-described point position adjustment is performed accordingly. The more time required, the longer the measurement time at each measurement point had a problem. In addition, for example, when a measurement item is changed, such as inspection of electrical characteristics between two points on a pad, there is a problem that a quick response thereto is impossible.

Therefore, the present invention devised to solve the above-mentioned problem, responds quickly and effectively, even if the measurement at various measurement points is required, the size of the device to be inspected is changed, or a new measurement item is required. Therefore, an object of the present invention is to provide an apparatus for measuring electrical characteristics on a wafer and a measuring method using the apparatus capable of performing an efficient measuring operation by greatly reducing the measuring time.

Figure 1 is a schematic diagram showing the configuration of one embodiment of an electrical characteristic measuring apparatus according to the prior art.

Figure 2 is a schematic diagram showing an embodiment configuration of an apparatus for measuring electrical characteristics according to the present invention.

Figure 3 is a front view schematically showing an electrical property measuring apparatus according to the present invention.

Explanation of symbols for main parts in the drawings

1: device body 2: measurement unit

3: control unit 11: probe card

12: pad 13: chuck

14, 22a, 22b: probe 21: probe mounting part

23: toggle switch

In order to achieve the above object, the present invention, the chuck means for seating the wafer on the upper surface; A probe having a first probe portion having a measuring pin connected to a positive (+) power line and a second probe portion having a measuring pin connected to a negative (-) power line and grounded, each probe contacting a plurality of measuring points on the wafer Way; The electrostatic source line and the fault to detect the electrical characteristics between the respective measuring points of the probe means and the electrical characteristics between the first probe portion and the chuck means and to output the detected values. Measuring means connected to one line; And a control means for receiving and processing the detected value, and outputting a control signal for releasing contact between the probe means and the corresponding measuring point of the pad after the measurement is completed. To provide.

The present invention also provides a chuck means for seating the wafer on the upper surface to ground; A first probe having a measuring pin connected to a positive power line and a plurality of measuring pins, each measuring pin having a second probe connected to a negative power line and grounded; Probe means for contacting a plurality of measurement points on a wafer seated at the wafer; Electrical characteristics at each line between one measuring point in contact with the first probe and another measuring point in contact with each measuring pin of the second probe, and between the first probe and the chuck means where the pad is seated and grounded. Measuring means connected to said electrostatic source line and said sub-power line for detecting electrical characteristics of said output and outputting respective detected values thereon; And a control means for receiving and processing the detected value, and outputting a control signal for releasing contact between the probe means and the corresponding measuring point of the pad after the measurement is completed. To provide.

In addition, in order to measure the DC parameters at a plurality of measurement points by using the electrical property measuring device, the present invention comprises the steps of mounting the ground on the upper surface of the chuck means; Providing a first probe portion and a second probe portion in contact with a plurality of measurement points on the wafer, connecting the first probe portion to a positive power line, and grounding the second probe portion to a negative power line; step; Measuring means connected to the electrostatic source line and the sub-power line to detect electrical characteristics between each measuring point contacted by the first and second probe portions, and between the measuring point of the first probe portion and the chuck means; Outputting a detection value; And receiving and processing the detected value, and outputting a control signal for releasing contact between the probe means and a corresponding measuring point of the wafer after the measurement is completed.

Hereinafter, with reference to the accompanying drawings, the configuration of an embodiment of the present invention will be described in detail.

Figure 2 schematically shows an embodiment configuration of the electrical characteristic measuring apparatus according to the present invention, Figure 3 schematically shows an electrical characteristic measuring apparatus equipped with a probe fixing part according to the present invention. As shown in the drawing, the present invention further provides a plurality of probes instead of a conventional probe card, and a plurality of probe fixing units for supporting position adjustment of the plurality of probes in order to enable measurement of various measurement points. Except as provided, the components having similar configurations to those of the related art are denoted by the same reference numerals, and the description thereof will be omitted.

In the electrical property measuring apparatus according to the present invention, as shown in Fig. 2, one is connected with a positive (+) power supply line drawn from the measurement unit 2 to be described later and the other is led to a switch 23 to be described later. Two probes 22a and 22b which are connected to a negative power line, which is connected to a negative power supply line and which has two measuring points on the pad 12 to be measured; Two probe mounting portions (21a, 21b) for supporting the probes (22a, 22b) through the support rods, respectively; The pad 12 to be measured is seated on an upper surface thereof, and a lower surface of the pad 12 is connected to a sub power supply line which is led to a switching switch 23 to be described later, and the chuck 13 electrically connecting the lower surface of the pad 12 to an earth ground. ; On each of the other probes 22b and the chuck 13 and on the secondary power line line between the measurement unit 2, either one of the probes 22b or the chuck 13 is selectively provided to the measurement unit 2 to be described later. Switching switch 23 for connection; Measure and measure the electrical properties between one probe 22a (power supply side) and grounded chuck 13 or between one probe 22a and another probe 22b (side, the line between two measuring points). A measurement unit 2 for sending out a measurement value; And processing the measured value received from the measurement unit 2 and sending a control signal to the apparatus main body 1 to release the contact state between the probes 22a and 22b and the measurement point, or to adjust the position of the chuck 13. It comprises a control unit 3 for resetting.

Hereinafter, the operation of the electrical characteristic measuring apparatus according to the present invention, each of the probe fixing unit (21a, 21b) is to support the probes (22a, 22b) to adjust the position by adjusting the length of the support rod, respectively The lower surface is provided with a means such as a magnet, and is easily attached to the upper surface of the device 1 by magnetic force. At this time, each of the probes 22a and 22b supported by the probe fitting portions 21a and 22b has the distance between the probes 22a and 22b adjusted so that a desired measuring point can be touched. Are arranged around. Subsequently, in order to position the pad 12 seated on the chuck 13 under the position-adjusted probe, the control unit 3 transmits a control signal to the apparatus body 1. When the pad 12 is in the touchable position, the probes 22a and 22b are brought into contact with the measuring point such that one probe 22a and the chuck 13 or between one probe 22a and the other probe 22b are in contact with each other. A predetermined voltage is applied to make it energized, and the electrical characteristics of the device are examined by measuring the DC-parameter according to the voltage applied by the measuring unit 2. That is, when the changeover switch 23 provided on the secondary power line electrically connects the chuck 13 and the measurement unit 2, a constant voltage is applied between one probe 22a and the chuck 13. The electrostatic source line, the probe 22a, the measuring point on the pad 12, the chuck 13, and the sub-power line (ground line of the chuck 13) become energized, and the measurement unit 2 is applied to the applied voltage. The current value is measured and the measurement result value is received and processed by the controller 3 to check, for example, the electrical connection state of the pad 12 and the diode characteristics at the protection gate. On the other hand, if the changeover switch 23 is to electrically connect the other probe 22b and the measurement unit 2, the voltage is between one probe (power supply side probe) 22a and the chuck 13. The electrostatic source line, one probe 22a, the pad 12, the other probe 22b, and the sub power supply line are energized, and likewise, the measurement unit 2 has a current value according to the applied voltage. And the result is received and processed by the control unit 3, for example, to examine the electrical properties between two measuring points on the pad 12 (i.e., a short circuit through a route other than the line between each probe). , Or measure the power dissipation in the line between each probe). In the above description, the case where the DC parameter is measured while the constant voltage is applied is described, but other DC parameters may be measured according to the energization of a constant current.

As described above, in addition to the conventional measurement items such as breakdown voltage (BV), constant current stress time (CCST), and the like, by employing a probe that can be adjusted in place of the conventional probe card, for example, It can also be applied to other metrics, such as a bridge, for measuring the electrical characteristics of a line between two measuring points. It is also possible to configure the device at a lower cost than using a probe card.

(Variation)

In the above description, although the two probes are provided to be limited to the electrical characteristic measuring device for measuring the DC parameters at the two measuring points, various modifications are possible as described below.

For example, if inspection of the electrical characteristics of a line between multiple measuring points is required, a number of other probes besides the power supply side probe may be provided, in which case one of the many other probes and the ground wire of the chuck is measured. By configuring the changeover switch to selectively connect with the unit, it is possible to measure the electrical parameters between the supply-side probe and each probe selected by the changeover switch (ie the line between one measuring point on the pad and the other measuring point selected). do.

In addition, for example, if it is necessary to simultaneously examine the electrical characteristics on the line between a plurality of measuring points, it may likewise be provided with a number of other probes and a plurality of measuring units in addition to the power supply side probe, in which case By measuring the DC parameters by providing a measuring unit of a connection between each one of the power supply side probes and each of the other probes, it is also possible to examine the electrical characteristics of the multiple lines between the power supply side probes and each of the other probes.

In addition, for example, when measurement at a plurality of measuring points is required, a plurality of power supply side probes may be provided, and each probe may be configured to be selectively connected to the meter through one changeover switch. In this case, it is possible to sequentially check the electrical connection state of the pads at the plurality of measuring points and the electrical characteristics of the diodes of the respective protection gates with the current value of the measuring unit according to the application of the voltage to each probe selected by the changeover switch. It becomes possible.

As described in the above modifications, the electrical property measuring apparatus according to the present invention can cope with a wider range of measurement items, and can be flexibly applied whenever a new measuring point is required.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.

According to the present invention having the above-described configuration, it can be applied to a wider range of measurement items, compared to the prior art, it is possible to increase the productivity due to the economic effect of configuring the device at a lower cost and shorter measurement time It works.

Claims (6)

Chuck means for seating the wafer on the upper surface to ground; A probe having a first probe portion having a measuring pin connected to a positive (+) power line and a second probe portion having a measuring pin connected to a negative (-) power line and grounded, each probe contacting a plurality of measuring points on the wafer Way; And the electrostatic source line and the power supply line for detecting electrical characteristics of the line between the measuring points contacted by the measuring pins of the probe means and electrical characteristics between the first probe part and the chuck means and outputting the detected values. An apparatus for measuring electrical characteristics of a wafer, comprising measuring means connected to a secondary power line. The wafer of claim 1, further comprising a switching means provided on the negative power line, wherein the second probe portion and the ground portion of the chuck are electrically connected to the measuring means through the switching means. Characteristic measuring device. The apparatus of claim 1 or 2, wherein the second probe portion comprises a plurality of measuring pins, and each measuring pin is selectively connected to the measuring means by the switching means. Chuck means for seating the wafer on the upper surface to ground; A first probe having a measuring pin connected to a positive power line and a plurality of measuring pins, each measuring pin having a second probe connected to a negative power line and grounded; Probe means for contacting a plurality of measurement points on a wafer seated at the wafer; And detecting an electrical characteristic at each line between one measuring point contacted by the first probe part and another measuring point contacted by each measuring pin of the second probe part, and an electrical property between the first probe part and the chuck means. And measuring means connected to the electrostatic power source line and the sub power supply line to output respective detection values. Mounting and grounding the wafer on the upper surface of the chuck means; Providing a first probe portion and a second probe portion having measurement pins respectively contacting a plurality of measurement points on the wafer, connecting the first probe portion to a positive power supply line, and connecting the second probe portion to a negative power supply line; Connecting to ground; Measuring means connected to the electrostatic source line and the sub-power line to provide electrical characteristics between each measuring point contacted by each measuring pin of the first and second probe portions, and between the measuring point of the first probe portion and the chuck means. Detecting and outputting the detected value; And receiving and processing the detected value, and outputting a control signal for releasing contact between the probe means and a corresponding measuring point of the wafer after the measurement is completed. The method of claim 5, further comprising: providing a switching means on a sub-power line to connect the second probe portion and the chuck ground portion to the measuring means, respectively, wherein the detecting of the electrical characteristics comprises: switching of the switching means. By means of measuring the electrical properties between the measuring point in contact with the first probe part and the measuring point in contact with the second probe part, and the electrical properties between the chuck means on which the first probe part and the wafer are seated and grounded. Method for measuring the electrical properties of the wafer to selectively measure the.