KR20100050807A - Pcm test pattern of metalization using damascene process and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A PCM test pattern for measuring a metal wiring using a damascene process and a manufacturing method thereof are provided to efficiently check the abnormality of the metal wiring process by monitoring an erosion in a CMP process. CONSTITUTION: A first probe pad(120) is connected on one side of a serpentine metal wiring(110). A second probe pad(130) is connected to the other side of the serpentine metal wiring. A plurality of contact plugs or via plugs(140) are formed on the lower side of the serpentine metal wiring with a constant space.

Description

PCM test pattern of metalization using damascene process and manufacturing method

The present invention relates to a PCM test pattern and a manufacturing method for measuring metal wiring by the inlay method, and more particularly, to a PCM test pattern and manufacturing by the inlay method that can monitor the erosion phenomenon occurring in the CMP process It is about a method.

In general, each semiconductor chip is made on a silicon wafer, and the process is normally monitored in a scribe lane between the interface of each semiconductor chip.

A certain pattern that can measure the characteristics and resistance of transistors used for this purpose is called a PCM (process change monitor, hereinafter referred to as a PCM) test pattern.

That is, after the semiconductor process is completed, the electrical characteristics of the semiconductor device are measured in the PCM test pattern to check whether the processes are normally performed and the characteristics of the unit device (transistor, metal wiring resistance, via resistance, etc.).

Among these test patterns, there is a pattern for measuring whether a metal wire is open or short. 1 is a schematic diagram showing a PCM test pattern for disconnection inspection of a conventional metallization, FIG. 2 is a schematic diagram showing a PCM test pattern for short-circuit inspection of a conventional metallization, and FIG. 3A forms a conventional PCM test pattern. 3B is a cross-sectional view illustrating a process of forming a metal wire on an actual chip.

By applying an electric signal to the test pattern as shown in FIG.

For example, in the case of a semiconductor device having six layers from the first metal wiring (hereinafter referred to as 'metal 1') to the sixth metal wiring (hereinafter referred to as 'metal 6'), the metal wiring is composed of metal 1 to metal. The PCM test patterns (hereinafter, referred to as 'open / short test patterns') (10 and 20) for disconnection or short circuit inspection respectively formed in Fig. 6 are tested to check whether each process proceeds normally.

However, the open / short test patterns 10 and 20 according to the related art have a problem in that they do not represent the situation of the actual process of applying the tungsten plug process and the damascene method considering only the distance and the width between the metal wires.

That is, as shown in the attached FIG. 3A, the pattern in the actual semiconductor chip is not only the distance and the width between the metal lines 30, but also the metal wiring layers at the bottom as shown in FIG. 3B. It consists of connecting contacts 40 or via contacts (not shown), which can lead to erosion or thinning when compared to conventional test patterns (see FIG. 3B). See the second figure).

In this case, the erosion phenomenon is referred to as a chemical mechanical polish (CMP) process. In the region of high pattern density, the polishing rate of the metal wiring portion and the insulation portion increases, so that the metal wiring is locally thin. It's a losing phenomenon.

Accordingly, an object of the present invention is to provide a PCM test pattern and a manufacturing method for measuring metal wiring by a damascene method that can monitor the erosion occurring in the CMP process.

PCM test pattern for measuring metal wiring by the inlay method of the present invention for realizing the object as described above is a metal wire formed of a superimposed '' 'shape; A first probe pad connected to one end of the sand metal wire; A second probe pad connected to the other end of the sand metal wire; And a plurality of contact plugs or via plugs formed on the lower portion of the sand metal wiring at regular intervals.

In addition, the sand metal wiring, the first probe pad and the second probe pad is characterized in that formed by the inlay method.

PCM test pattern for measuring metal wiring by the inlay method of the present invention comprises a first comb metal wiring made of a plurality of overlapping fingers; A second comb metal wire formed of a plurality of fingers overlapping a predetermined distance between the plurality of fingers of the first comb metal wire; A first probe pad connected to one end of the first comb metal wire; A second probe pad connected to one end of the second comb metal wire; And a plurality of contact plugs or via plugs formed at a predetermined interval under the first comb metal wiring and the second comb metal wiring.

The first comb metal interconnection, the second comb metal interconnection, the first probe pad, and the second probe pad may be formed by a damascene method.

In addition, the contact plug or via plug may be formed by a process of depositing tungsten metal by chemical vapor deposition and a chemical mechanical polishing process of tungsten metal.

PCM test pattern manufacturing method for measuring the metal wiring by the inlay method of the present invention includes a plug forming step of forming a contact plug or via plug by the deposition process of tungsten metal by the chemical vapor deposition method and the chemical mechanical polishing process of tungsten metal; A trench forming step of forming a trench pattern for metal wiring by performing a photolithography process and an etching process after depositing an interlayer insulating film; An ECP step of forming a copper metal by an electrochemical plating method; And a wiring forming step of patterning the metal wiring by a chemical mechanical polishing process of the copper metal.

According to the PCM test pattern and manufacturing method for measuring metal wiring by the inlay method according to the present invention by monitoring the erosion phenomenon occurring in the CMP process has the effect that can be effectively confirmed whether the abnormality in the actual metal wiring process.

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the preferred embodiment of the present invention will be described in detail so that those skilled in the art can easily practice.

Example 1

4 is a layout diagram of a PCM test pattern for confirming disconnection of wiring according to an embodiment of the present invention, and FIG. 5 is a layout of a PCM test pattern for confirming whether a wiring is shorted in one embodiment of the present invention. It is also.

As shown in FIG. 4, the PCM test pattern 100 for measuring metal wiring by the inlay method according to an embodiment of the present invention includes a sand metal wiring 110, a first probe pad 120, and a second The probe pad 130 and the contact plug (or via plug) 140 are included.

The serpentine metal wire 110 has an overlapped 'L' shape, and this structure is used to check the continuity of the metal wire. That is, when disconnection occurs in the sand metal wire 110 due to a certain process factor (pattern defect or particle, etc.), the measured resistance value indicates a Giga Ohm level value.

The first probe pad 120 is a substantially square metal pattern connected to one end of the sand metal wire 110, and the second probe pad 130 is connected to the other end of the sand metal wire 110. Metal pattern. The first probe pad 120 and the second probe pad 130 are portions in which probes of a tester are in contact with each other, and a probe pad having a size of 100 μm × 100 μm is generally used. .

Here, the sand metal wiring 110, the first probe pad 120, and the second probe pad 130 are preferably formed by a single damascene process.

The contact plug 140 or the via plug is a plurality of plugs formed at regular intervals below the sand metal wiring, and has a structure similar to that of an actual semiconductor chip.

The contact plug 140 or the via plug may be formed by a deposition process of tungsten metal by chemical vapor deposition and a chemical mechanical polishing process of tungsten metal.

Example 2

As shown in FIG. 5, the PCM test pattern 200 for measuring metal wiring by the inlaying method according to another embodiment of the present invention includes a first comb metal wiring 210 and a second comb metal wiring 220. ), A first probe pad 230, a second probe pad 240, and a contact plug (or a via plug).

The first comb metal wire 210 is a metal pattern formed by a plurality of fingers overlapping each other. In addition, the second comb metal line 220 is a metal pattern formed by overlapping a plurality of fingers formed by a predetermined distance between the plurality of fingers of the first comb metal line 210.

The first probe pad 230 is a substantially rectangular metal pattern connected to one end of the first comb metal wiring 210, and the second probe pad 240 is formed of the second comb metal wiring 220. It is a roughly rectangular metal pattern connected to one end.

As described above, the first probe pad 230 and the second probe pad 240 are portions in which the probes of the test equipment are in contact with each other, and a probe pad having a size of 100 μm × 100 μm is generally used.

Here, the first comb metal wiring 210, the second comb metal wiring 220, the first probe pad 230, and the second probe pad 240 may be formed by an inlay method.

This structure is used to check whether there is a short circuit between the first comb metal wiring 210 and the second comb metal wiring 220. That is, when a short occurs in the sand metal wiring due to a certain process factor (such as a bad pattern or a particle), a current of micro ampere flows.

The contact plug or the via plug is a plug which is formed in plural at regular intervals under the first comb metal wiring and the second comb metal wiring, and has a structure similar to that of an actual semiconductor chip.

Here, the contact plug 250 or the via plug may be formed by a tungsten metal deposition process by chemical vapor deposition and a chemical mechanical polishing process of tungsten metal.

Therefore, according to the PCM test pattern for metal wiring measurement by the inlay method according to a preferred embodiment of the present invention, contacts or via contacts for connecting the metal wiring layers are added to the lower part of the open / short test pattern. It is possible to monitor the presence of abnormality of the process more accurately by having a structure similar to the actual semiconductor chip.

Example 3

PCM test manufacturing method for measuring metal wiring by the damascene method according to an embodiment of the present invention comprises a plug forming step, trench forming step, ECP step and wiring forming step.

The plug forming step is a step of forming a contact plug or a via plug by a deposition process of tungsten metal by chemical vapor deposition and a chemical mechanical polishing process of tungsten metal.

At this time, as shown in the second figure of FIG. 3B, erosion may occur by a chemical mechanical polishing process in a region having a high pattern density.

The trench forming step is a step of forming a trench pattern for metal wiring by depositing an interlayer insulating film and then performing a photolithography process and an etching process. Here, the deposited shape of the interlayer insulating film is also formed by the erosion phenomenon as shown in the third drawing of FIG. 3B.

The ECP step is to form a copper metal by electrochemical plating, and the wire forming step is to pattern metal wiring by a chemical mechanical polishing process of copper metal.

Thus, as shown in the fourth and fifth figures of FIG. 3B, a thin copper metal layer (the 'a' portion of the fifth figure of FIG. 3B) remains between the metal lines to be formed.

According to the PCM test manufacturing method for measuring the metal wiring by the damascene method according to the embodiment of the present invention, there is an advantage that can be confirmed more reliably than when using only conventional metal wiring.

It is apparent to those skilled in the art that the present invention is not limited to the above-described embodiments and can be practiced in various ways within the scope not departing from the technical gist of the present invention. It is.

1 is a schematic view showing a PCM test pattern for disconnection inspection of a conventional metallization,

2 is a schematic view showing a PCM test pattern for short-circuit inspection of a conventional metallization,

3A is a cross-sectional view illustrating a process of forming a conventional PCM test pattern;

3B is a cross-sectional view illustrating a process of forming a metal wiring on an actual chip;

4 is a layout diagram of a PCM test pattern for confirming disconnection of wiring according to an embodiment of the present invention;

5 is a layout diagram of a PCM test pattern for confirming whether a wiring is shorted in an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: open test pattern 20: short test pattern

30: metal wiring 40: contact

50, 150 semiconductor substrate 61 first insulating film

62: second insulating film 100, 200: PCM test pattern

110: sand metal wiring 120: first probe pad

130: second probe pad 140, 250: contact plug

210: first comb metal wiring 220: second comb metal wiring

230: first probe pad 240: second probe pad

Claims (6)

A square metal wire formed of an overlapping 'ㄹ' shape; A first probe pad connected to one end of the sand metal wire; A second probe pad connected to the other end of the sand metal wire; And a plurality of contact plugs or via plugs formed in a plurality at regular intervals below the sand metal wiring. The PCM test pattern of claim 1, wherein the sand metal wiring, the first probe pad, and the second probe pad are formed by a damascene method. A first comb metal wire formed of a plurality of overlapping fingers; A second comb metal wire formed of a plurality of fingers overlapping a predetermined distance between the plurality of fingers of the first comb metal wire; A first probe pad connected to one end of the first comb metal wire; A second probe pad connected to one end of the second comb metal wire; And a plurality of contact plugs or via plugs formed at a plurality of predetermined intervals below the first comb metal wiring and the second comb metal wiring. 2. 4. The PCM test pattern of claim 3, wherein the first comb metal wiring, the second comb metal wiring, the first probe pad, and the second probe pad are formed by a damascene method. . The method of claim 1 or 3, wherein the contact plug or via plug is formed by a process of depositing tungsten metal by chemical vapor deposition and chemical mechanical polishing process of tungsten metal. PCM test pattern for measurement. A plug forming step of forming contact plugs or via plugs by a deposition process of tungsten metal by chemical vapor deposition and a chemical mechanical polishing process of tungsten metal; A trench forming step of forming a trench pattern for metal wiring by performing a photolithography process and an etching process after depositing an interlayer insulating film; An ECP step of forming a copper metal by an electrochemical plating method; And a wiring forming step of patterning a metal wiring by a chemical mechanical polishing process of copper metal. 2.

Images