JPS63179541A - Evaluation of semiconductor element - Google Patents

Abstract

PURPOSE:To facilitate the analysis of a minute region, by measuring currents flowing through a plurality of wiring metals, which are attached on an electrode, and detecting a place, where the currents are generated in the electrode. CONSTITUTION:An oxide film 2 is formed on a semiconductor substrate. An electrode (gate electrode) 3 is formed on the oxide film 2. Field oxide films 12 are formed on both sides of the gate electrode 3. Thereafter, wiring metals 13 are individually contacted with the four corners of the gate electrode 3 so that pads are formed on the field oxide film 12. Ammeters 14-17 are individually connected to the wiring metals 13. The wiring metals 14-17 are grounded through the ammeters 14-17. Then currents through the wiring metals 13 are measured. Thus the generation of the currents in the electrode 3 is detected. In this way the analysis and clarification of the minute region of the electrode can be made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for evaluating MO8 type semiconductor or Schottky semiconductor devices.

(Prior Art) Conventionally, this type of evaluation method is disclosed in Japanese Patent Application Laid-open No. 54-102978 and Japanese Patent Application Laid-open No. 54-26667.

This evaluation method will be explained below based on FIGS. 4(a) and 4(b). First, FIG. 4(A) is a cross-sectional view illustrating a method for evaluating leakage current of a MOS canontor.

That is, a part of the semiconductor substrate 1 is oxidized to form an oxide film 2.
After forming, an f- upper electrode 3 is formed on the oxide film 2 to form a MOS capacitor. Further, a power source 4 is connected to the electrode 3, and the substrate 1 is grounded via an ammeter 5.

While applying voltage to the stain electrode 3 from the power source 4,
The ammeter 5 was used to measure the leakage current flowing to the substrate 1 through the oxide film 2. Next, Figure 4 (b) shows Mo
FIG. 2 is a cross-sectional view illustrating a method for evaluating the current flowing through the oxide film 2 when electrons and holes from the substrate 1 are avalanche-injected into the oxide film 2 of the s-transistor. That is, a source region 6 and a drain region 7 are formed on both sides of a MOS capacitor formed by sequentially forming an oxide film 2 and an electrode 3 on a semiconductor substrate 1, and the substrate 1 and the drain region 7 are connected to each other.

While connecting power supplies 8 and 9 to the rain region 7, respectively,
The source region 6 is grounded, and the oxide film 2 is also grounded via an ammeter 10. In this way, when a voltage is applied between the drain region 7 and the substrate 1 by the power supplies 8 and 9, the depletion layer 11 formed in the substrate 1 due to the voltage applied between the source region and the drain region is caused by an avalanche phenomenon. A pair is created between an electron and a hole. As a result, the current generated is detected by the ammeter 10 through the oxide film 2.

(Problems to be Solved by the Invention) However, in the conventional semiconductor device evaluation method, all of the current that entered the dart electrode 3 was measured, so the location where the current was generated could not be ascertained, and Ninth, there was a problem in that it was not possible to investigate the cause or analyze the mechanism related to current generation.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a semiconductor device evaluation method that can measure the current generated in a minute region of a semiconductor device.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes mounting a plurality of wiring metals 13 on the electrode 3 of the semiconductor substrate 1 and measuring the current of each wiring metal 13. This is to detect the location where the current is generated within the electrode 3.

(Function) In the present invention, the currents flowing through a plurality of wiring metals are individually measured and the locations where the currents are generated are detected, thereby facilitating the analysis and elucidation of minute regions of the electrodes.

(Embodiment) Hereinafter, an embodiment of the present invention will be described based on the drawings, with the same components as those of the conventional example being denoted by the same reference numerals. Figure 1 is a cross-sectional view illustrating the measurement method for semiconductor devices.
The figure is a plan view and a third
The figure is an explanatory diagram showing the principle of the measurement method.

That is, in the method for evaluating a semiconductor element, an oxide film 2 is formed on a semiconductor substrate 1, and an electrode (y-meter electrode) 3 is formed on the oxide film 2. Next, a field oxide film 12 is formed on both sides of the dirt electrode 3, and then wiring metal 13 is brought into contact with each of the four sides of the f-1 electrode 3, and on the field oxide film 12, a metal layer 12 is formed on each side. form like this. In this case, it is desirable that the r-meter electrode 3 has a higher resistance value than the wiring metal 13. Generally, Lindog polysilicon is used for the r-meter electrode 3, and aluminum wiring is used for the wiring metal 13. is used. Furthermore, ammeters 14.15 and 16.17 are individually connected to each of the wiring metals 13, and each of the wiring metals 13 is grounded through the ammeters 14.15 and 16.17, respectively.

Therefore, for example, as shown in FIG.
Assume that the leak occurs at point 9. In this case, if the distance from point X to each wiring metal 13 is 4+11.4+'4, and the resistance is Rt, &, Rs, R4, and the specific resistance of f-) electrode 3 is ρG, then R1'' I
dGll(1) R,oc pG4(2
) & ocpG/a (
3)&■-〇! 4 (4
) holds true. Therefore, Q), (2),
(3), (4) Resistance R8, R,, R4
is proportional to the distance /, , /oez,a14.

Also, the resistance of the wiring metal 13 is rl l rl m rl
If t r4 is established between the specific resistance ρm of the wiring metal 13 and the specific resistance ρG of the r-meter electrode 3, then the following equation holds from equation (5). .

f, Qll l", #vr3-r4-Q
(6) Then, the current flowing through each wiring metal 13 is il.

t, 111 s t4, then 11+ it + is + it wealth 1 (7) Rs i
s ” R11! = Rs fa = & it
(8) holds true. Thus, (1)
e (2), (3), (4), (6),
(7).

Equation (8) holds the following equation.

1+ it = lx is = Is i, -= /
414(9) Therefore, i, s it l t, a
The value of 14 is measured using an ammeter 14.15°16.17, and the formula (9) is expressed as ! If t t t, 14 #m is calculated, the X point can be specified. In this way, r-) electrode 3
It becomes possible to analyze and elucidate minute areas within the area.

(Effects of the Invention) As explained above, according to the present invention, the current flowing through a plurality of wiring metals attached to the electrode is measured and the location where the current is generated within the electrode is detected. Since analysis is possible, the above-mentioned problems can be solved by investigating the cause of leakage current generation and elucidating mechanisms such as withstand voltage.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention. FIG. 1 is a cross-sectional view explaining the method of the present invention. FIG. 2 is a plan view explaining the method of the present invention. FIGS. 4A and 4B are cross-sectional views illustrating the conventional method. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 3... Electrode (f-upper electrode), 1
3... Wiring metal. Main party bound eyebrow f: left explanation 15mo 92

Claims (1)

[Claims] 1. A method for evaluating a semiconductor device, comprising: attaching a plurality of wiring metals on an electrode of a semiconductor substrate; and detecting a location where a current is generated in the electrode by measuring the current of each wiring metal.