JPH04342152A - Semiconductor measuring device - Google Patents

Abstract

PURPOSE:To prevent reflection wave generated by mismatching of impedance. CONSTITUTION:A semiconductor measuring device is provided with an input side probe needle 10 and an output side probe needle and the input side probe needle 10 is provided with a coplaner type transmission line formed on a ceramic substrate. The input side probe needle 10 forms a coplaner type transmission line in both sides of the ceramic substrate. A signal line and a grounding line of each of coplanar type transmission line of both sides are connected each other at a side of a substrate end and a thin resistance 10a is formed between a signal line and a grounding line of a substrate surface. Since the thin film resistance 10a is close to a gate electrode of an FET, reflected waves caused by mismatching of impedance are not generated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a semiconductor measuring device.
In particular, the present invention relates to a semiconductor measuring device that measures pulse response characteristics of high-frequency FETs on a wafer.

0002

BACKGROUND OF THE INVENTION First, the prior art will be explained with reference to the drawings. 5 to 7 are enlarged views of a probe needle portion of a conventional semiconductor measuring device. In Figures 5 and 6, 1 is F
It is a chip on which an ET is formed, and on its surface, the input side has a source electrode 1a-gate electrode 1b-source electrode 1a, and the output side has a source electrode 1a-drain electrode 1.
Electrode pads are formed in the order of c-source electrode 1a. As shown in FIG. 7, the probe needles 5 and 6 have a ground line 7 and a signal line 8, and are constructed by forming a coplanar transmission line on the back surface of a ceramic substrate. These probe needles 6 and 7 are connected to the electrode pads 1a to 1c of the FET as shown in FIG.

FIG. 8 is an equivalent circuit diagram of a pulse response measurement system of a conventional measurement device. The drain electrode 1c of the FET 1 is connected to a 50Ω load resistor 4 at a connection point B via a back coplanar probe needle 3 and a 50Ω coaxial line 41. The other end of the load resistor 4 is connected to a drain bias power supply 7. In order to observe the voltage at connection point B, a 450Ω resistor 5 is connected to point B as a probe resistor, and the other end of the probe resistor 5 is connected to an oscilloscope 6 with an input impedance of 50Ω.

[0004] The gate electrode of the FET 1 is connected to point A by a back coplanar probe needle 2 . Point A is connected to a pulse pattern generator 9 with an input impedance of 50Ω via a coaxial line, and is grounded via a 50Ω terminating resistor 50.

In this measurement system, a pulse pattern generator 9 generates a pulse wave, and when the pulse wave is applied to the gate electrode of the FET 1, the response of the drain current is observed as a voltage change at point B due to the load resistor 4.

[0006] At point B, there is a probe resistance of 450Ω and a probe resistance of 50Ω.
Since a resistance of 500Ω is connected including the resistance of the oscilloscope, the oscilloscope has a resistance of 500Ω: 5
The voltage change at point B can be observed with a ratio of 0Ω=10:1.

[0007]

[Problems to be Solved by the Invention] Since the gate electrode of FET 1 usually has a high impedance, unless the 50Ω terminating resistor is placed as close to the gate electrode as possible, the pulse response characteristics will deteriorate due to reflected waves caused by impedance mismatch. cannot be observed accurately.

However, in this conventional semiconductor measuring device, the point A to which the 50Ω terminating resistor 10 is connected and the FET
is connected to the gate electrode by a back coplanar probe needle 2, and this distance is usually several mm, so
Due to the reflected waves caused by the impedance mismatch mentioned above,
There was a problem that accurate observation of pulse response characteristics was not possible.

[0009]

[Means for Solving the Problems] The gist of the present invention is a semiconductor measuring device that is used to measure the characteristics of a field effect transistor formed on a semiconductor chip and includes a probe needle made of a coplanar transmission line formed on a substrate. In this method, coplanar transmission lines are formed on both sides of the substrate of the probe needle connected to the gate electrode of the field effect transistor, and the signal lines and ground lines of the coplanar transmission lines on both sides are connected on the side of the substrate. , a thin film resistor is formed between the signal line and the ground line on the surface of the substrate.

0010

The probe needle according to the present invention is connected to the gate electrode of a field effect transistor to be measured, and supplies an input signal to the field effect transistor through the probe needle. The thin film resistor on the probe needle and the gate electrode are very close to each other, and no reflected waves are generated due to impedance mismatch.

[0011]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged view showing a probe needle 10 of a semiconductor measuring device according to an embodiment of the present invention. 2 and 3 show a state in which the probe needles 10 and 11 are brought into contact with a chip 12 on which an FET is formed. 2 and 3, the FET chip 12 is arranged on its surface in the order of source electrode 12a-gate electrode 12a-source electrode 12a on the input side, and in the order of source electrode 12a-drain electrode 12c-source electrode 12a on the output side. Electrode pads are formed.

The probe needle 10 on the input side forms a coplanar transmission line on both the front and back sides of a ceramic substrate, and connects each signal line 10b of the coplanar transmission line on the side of the substrate.
and the ground wire 10c, and connect the signal wires 10b and 2 on the board surface.
A thin film resistor 10a made of, for example, TaN2 or the like is formed between each ground line 10c.

The resistance value of each thin film resistor 10a is set to 1.
When set to 00Ω, the signal line 10 to the gate electrode 12b
b is folded back close to the gate electrode and terminated at 50Ω.

The probe needle 11 on the output side is constructed by forming a coplanar transmission line only on the back surface of a ceramic substrate. These probe needles and FET electrode pads are shown in Figure 2.
〜Connected in the state shown in FIG.

FIG. 4 is an equivalent circuit diagram of the pulse response measurement system. The drain electrode 12c of the FET 12 is connected to a 50Ω load resistor 42 at a connection point B via the back coplanar probe needle 11 and a 50Ω coaxial line 41. The other end of the load resistor 42 is connected to a drain bias power supply 43. In order to observe the voltage at connection point B, a 450Ω resistor 44 is connected to point B as a probe resistor, and the other end of the probe resistor 44 is connected to an oscilloscope 45 having a 50Ω input impedance.

The gate electrode 12b of the FET 12 is connected to point A by a double-sided coplanar probe needle 10. A
The point is connected to the pulse pattern generator 47 by the coaxial line 46.
connected to. This signal line is terminated at 50Ω by a thin film resistor 10a on the surface of the double-sided coplanar probe needle 10.

In this measurement system, when a pulse wave is generated by the pulse pattern generator 9 and applied to the gate electrode 12b of the FET 12, the response of the drain current is observed as a voltage change at point B due to the 50Ω load resistor 42. At point B, a probe resistance 44 of 450 Ω and an oscilloscope 45 of 50 Ω are connected, totaling 500 Ω.
Since this resistor is connected, the oscilloscope 45 can observe the voltage change at point B at a ratio of 500Ω:50Ω=10:1.

Compared to the conventional measurement system, since the input signal is folded back at the tip of the probe needle 10 and terminated at 50Ω, almost no reflected waves are generated due to impedance mismatch.

[0019]

As explained above, in the present invention, since the terminating resistor is formed on the probe needle, the input signal can be folded back and terminated in the vicinity of the FET gate electrode, thereby preventing reflection of the input signal due to impedance mismatch. can be suppressed. Therefore, it has the effect of improving observation accuracy in observing pulse response characteristics.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a probe needle according to an embodiment of the present invention.

FIG. 2 is a side view showing a state of contact between a probe needle and a tip according to an embodiment of the present invention.

FIG. 3 is a plan view showing a state of contact between a probe needle and a tip according to an embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram showing a measurement system using a probe needle according to an embodiment of the present invention.

FIG. 5 is a plan view showing a state of contact between a conventional probe needle and a tip.

FIG. 6 is a side view showing a state of contact between a conventional probe needle and a tip.

FIG. 7 is a perspective view showing a conventional probe needle.

FIG. 8 is an equivalent circuit diagram showing a measurement system using a conventional probe needle.

[Explanation of symbols]

10 Double-sided coplanar probe needle 10a Thin film resistor 11　Back side coplanar type probe needle 12 Chip 12a Source electrode 12b Gate electrode 12c Drain electrode

Claims (2)

[Claims] 1. A semiconductor measuring device that is used to measure the characteristics of a field effect transistor formed on a semiconductor chip and includes a probe needle made of a coplanar transmission line formed on a substrate, wherein the gate electrode of the field effect transistor is Coplanar transmission lines are formed on both sides of the board of the probe needle to be connected to the board, and the signal lines and ground lines of the coplanar transmission lines on both sides are connected on the side of the board, and the signal line and ground line on the board surface are connected. A semiconductor measuring device characterized in that a thin film resistor is formed between the semiconductor measuring device and the semiconductor measuring device. 2. The thin film resistor functions as a terminating resistor for an input signal system supplied to the gate electrode of the field effect transistor, and the output signal system is connected to the drain electrode of the field effect transistor via another probe needle. Claim 1
The semiconductor measuring device described.