JP2010169638A - Fine needle, method of manufacturing the same, electric characteristic evaluating method, and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine needle significantly reducing the value and variation of contact resistance, a method of manufacturing the fine needle, an electric characteristic evaluating method using the fine needle, a method of manufacturing a semiconductor device, and the like. <P>SOLUTION: In this method of manufacturing the needle, by irradiating the tip of the needle made of tungsten 1a with ion beams formed of gallium ions 4, argon ions, iodine ions, or cesium ions, a surface layer 3a containing gallium, argon, iodine, or cesium is formed at the tip of the needle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fine needle, a fine needle manufacturing method, an electrical property evaluation method, a semiconductor device manufacturing method, and the like, and in particular, a fine needle capable of greatly reducing the value and variation of contact resistance, a fine needle manufacturing method, The present invention relates to a method for evaluating electrical characteristics using a fine needle, a method for manufacturing a semiconductor device, and the like.

  In evaluating the electrical characteristics of the elements inside the device in the semiconductor device, the electrical characteristics are evaluated by bringing a fine needle into direct contact with the PAD drawn from the element electrodes or vias connected to the electrodes. The fine needle is produced by performing electropolishing in an aqueous potassium hydroxide solution and washing in the order of 80 ° C. water and ethanol. In addition, tungsten, which is hard and has excellent wear resistance, is often used as the material for the fine needles (see, for example, Patent Document 1).

JP 2006-49599 A (paragraphs 0001 to 0005)

  FIG. 6 is a diagram showing a component analysis result of a surface layer of a conventional fine needle. However, this is a result of component analysis performed on the side surface instead of the tip of the fine needle in consideration of the measurement accuracy of the component analysis. As shown in FIG. 6, it can be seen that an oxide film layer composed of carbon and oxygen is attached to the surface of the fine needle. That is, a natural oxide film is formed on the surface layer of the fine needle made of tungsten. Because this natural oxide film adheres to the surface of the fine needle, when the fine needle is brought into contact with the PAD drawn out from the device electrode or directly into the via, the contact resistance variation value is high and high accuracy analysis is possible. I can't.

  The present invention has been made in consideration of the above, and an aspect according to the present invention is a fine needle that can significantly reduce the value and variation of contact resistance by suppressing the adhesion of a natural oxide film, These include a method for manufacturing a fine needle, a method for evaluating electrical characteristics using the fine needle, a method for manufacturing a semiconductor device, and the like.

In order to solve the above problems, a fine needle according to one aspect of the present invention includes a needle made of metal,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
It is characterized by comprising.

  According to the fine needle, the surface layer containing gallium, argon, iodine or cesium formed at the tip of the needle is formed. As a result, the value and variation of the contact resistance are greatly reduced, and a natural oxide film is hardly generated, and the state in which the value and variation of the contact resistance are greatly reduced can be maintained for a long time.

  In the fine needle according to the present invention, it is preferable that the diameter of the needle is 10 μm or less.

  In the fine needle according to the present invention, the metal is preferably tungsten.

  In the method for producing a fine needle according to the present invention, the tip of the needle is irradiated with an ion beam of gallium ion, argon ion, iodine ion, or cesium ion, so that the tip of the needle is gallium, argon, iodine, or A surface layer containing cesium is formed.

According to the electrical property evaluation method of the present invention, a semiconductor device or an electrode electrically connected to the semiconductor device is brought into contact with a fine needle, and a signal is input to the semiconductor device or the electrode through the fine needle. An electrical property evaluation method comprising a step of evaluating
The fine needle is
A metal needle,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
It is characterized by comprising.

In the method for manufacturing a semiconductor device according to the present invention, a fine needle is brought into contact with a semiconductor device or an electrode electrically connected to the semiconductor device, and a signal is input to the semiconductor device or the electrode through the fine needle. A method of manufacturing a semiconductor device including a step of evaluating characteristics,
The fine needle is
A metal needle,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
It is characterized by comprising.

(A) And (b) is a figure for demonstrating the manufacturing method of the fine needle | hook concerning embodiment of this invention. The figure which shows the component analysis result of the surface layer of the fine needle after the ion beam irradiation which concerns on embodiment of this invention. The figure for demonstrating a contact resistance measurement. (A) And (b) is a figure which shows the component analysis result of the surface layer formed in the front-end | tip part of the microneedle which concerns on embodiment of this invention. Sectional drawing for demonstrating the electrical property evaluation method of the semiconductor device which concerns on embodiment of this invention. The figure which shows the component analysis result of the surface layer of the conventional fine needle | hook. The figure which shows the component analysis result of the front-end | tip part of the conventional fine needle | hook.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1A and 1B are diagrams for explaining a method of manufacturing a fine needle according to an embodiment of the present invention.

  As shown in FIG. 1A, a fine needle 1a having a diameter of, for example, 0.1 to 0.2 μm is set in a vacuum chamber of a FIB (focused ion beam) apparatus. The material of the fine needle 1a is preferably a metal, such as tungsten. A natural oxide film 2a is attached to the surface of the fine needle 1a. Next, the tip of the fine needle 1a is irradiated with an ion beam using gallium ions 4. At this time, as an example of the ion beam to be used, the acceleration voltage is 30 kV, the probe current is 320 pA, the beam diameter is 54 nm, and the processing conditions are the etching depth of 30 nm. In this embodiment, the diameter of the fine needle is 0.1 to 0.2 μm. However, the diameter is not limited to this range, and the diameter of the fine needle of the present invention may be various as long as it is 10 μm or less. The diameter can be used, more preferably 1 μm or less.

  A sputtering phenomenon occurs by an ion beam using gallium ions 4, and the natural oxide film 2b and tungsten 1b adhering to the surface of the fine needle 1a are knocked out in a vacuum.

  Next, as shown in FIG. 1B, the tip of the fine needle 1a irradiated with the ion beam is removed of the natural oxide film 2a attached to the surface and a part of the fine needle 1a. Thereafter, a surface layer 3a containing gallium in tungsten is formed on the surface of the exposed tip of the fine needle 1a. The thickness of the surface layer 3a is preferably 1 to 20 nm.

  In this embodiment, the surface layer 3a containing W and Ga is formed by irradiating the tip of the fine needle 1a with an ion beam of Ga ions. However, Ar ion, I ion, or Cs is formed on the tip of the fine needle. A surface layer containing W and Ar or I or Cs may be formed by irradiation with an ion beam of ions.

  FIG. 2 is a diagram showing component analysis of the surface layer 3a of the fine needle 1a after the ion beam irradiation with the gallium ions 4 shown in FIG. 1 (b). In consideration of the measurement accuracy of the component analysis, the component analysis is performed on the side surface instead of the tip of the fine needle 1a. At this time, the surface layer 3a in which gallium is contained in tungsten is formed on the side surface portion of the fine needle 1a by irradiating an ion beam with gallium ions 4 in the same manner as the tip portion. In the component analysis shown in FIG. 2, it can be seen that the components of carbon and oxygen constituting the natural oxide film 2a are reduced as compared with the component analysis of the surface layer 3a of the conventional fine needle 1a shown in FIG. Furthermore, it can be read that the surface layer 3a of the fine needle 1a contains a gallium component.

  FIG. 3 is a diagram for explaining the contact resistance measurement by the fine needle 1a. As shown in FIG. 3, there is a W plug 32 for electrically connecting an Al film 31 formed on the insulating film 30. The fine needle 1a shown in FIG. A voltage is applied from a power source connected to 1a. At this time, the applied voltage is V, the current is I, and the contact resistance is V / 2I.

  Six microneedles as described above were prepared, and the contact resistance of each microneedle was measured. The average value AVE of the contact resistances and the standard deviation σ indicating variations in the contact resistance are shown in Table 1. Moreover, the component analysis result of the surface layer 3a formed in the front-end | tip part of the fine needle | hook mentioned above is shown to Fig.4 (a). Further, FIG. 4B shows the component analysis result of the surface layer 3a formed at the tip of the fine needle after the fine needle described above is left in the atmosphere for 30 days immediately after the ion beam irradiation.

  Table 1 shows the standard deviation indicating the average value AVE of the contact resistance and the variation in the contact resistance after measuring the contact resistance by the method described above after leaving the above-mentioned fine needle in the air atmosphere for 7 days and 80 days. Table 1 shows σ.

  Table 1 also shows that six conventional fine needles that are not irradiated with an ion beam of gallium ions are prepared, the contact resistance of each fine needle is measured, the average value AVE of the contact resistances, and the variation in contact resistance. Table 1 shows the standard deviation σ indicating Moreover, the component analysis result of the front-end | tip part of the conventional fine needle | hook mentioned above is shown in FIG.

  As shown in Table 1, the contact resistance of the conventional fine needle without ion beam irradiation is AVE = 4.1E + 7 and σ = 7.9E + 7, whereas the contact resistance of the fine needle immediately after ion beam irradiation is AVE. = 11.7 and σ = 4.0. According to the component analysis at the tip of the conventional fine needle without ion beam irradiation shown in FIG. 7, oxygen is detected and a natural oxide film is formed on the surface of the fine needle. From the component analysis at the tip of the fine needle immediately after the ion beam irradiation, it is understood that oxygen is not detected and a natural oxide film is not formed. Moreover, since the tip part of the fine needle 1a has a needle shape and is not constant in thickness, the measurement accuracy of component analysis is lower than that of the side part. Therefore, a trace amount of gallium contained in the surface layer 3a is not detected.

  In addition, the contact resistance of the fine needle 7 days after the ion beam irradiation is AVE = 12.6Ω and σ = 4.1, and it can be seen that there is almost no change immediately after the treatment. Further, even in the fine needle 80 days after the ion beam irradiation, the contact resistance is AVE = 12.4Ω and σ = 4.2, and it can be seen that there is almost no change immediately after the treatment. Further, according to the component analysis of the surface layer 3a formed at the tip of the fine needle 1a 30 days after the ion beam irradiation shown in FIG. 4B, oxygen is detected almost the same as immediately after the ion beam irradiation. It can be seen that a natural oxide film is not formed.

  Next, a method for evaluating the electrical characteristics of the semiconductor device using the fine needle shown in FIG. FIG. 5 is a cross-sectional view illustrating a method for evaluating electrical characteristics of a semiconductor device according to an embodiment of the present invention.

  As shown in FIG. 5, a LOCOS oxide film 11 which is an element isolation film is formed on the surface of the silicon substrate 10. Next, a gate oxide film to be the gate insulating film 12 is formed on the surface of the silicon substrate 10 by a thermal oxidation method. Next, a polysilicon film is formed on the gate insulating film 12 and the LOCOS oxide film 11 by a CVD (Chemical Vapor Deposition) method, and this polysilicon film is processed and formed by a photolithography method and a dry etching method. Thereby, the gate electrode 13 is formed on the gate insulating film 12. Next, a diffusion layer 24 in the LDD region is formed on the silicon substrate 10.

  Next, for example, a silicon nitride film is formed on the entire surface of the substrate including the gate electrode 13 and the LOCOS oxide film 11 by a CVD method. Thereafter, the silicon nitride film is etched by the etch back method, whereby the sidewalls 14 are formed on the side walls of the gate electrode 13. Next, a diffusion layer 23 in the source / drain region is formed. Next, a first interlayer insulating film 22 is formed on the entire surface of the substrate including the gate electrode 13, the sidewalls 14, and the LOCOS oxide film 11 by the CVD method. Thereafter, holes are formed in the first interlayer insulating film 22. Next, a metal film is formed in the hole and on the first interlayer insulating film 22 by a sputtering method, and then the metal film on the first interlayer insulating film 22 is removed by a CMP method, thereby removing the first film. Plug 15 is formed. Thereafter, a wiring layer is formed on the first interlayer insulating film 22 and the first plug 15 by a sputtering method, and this wiring layer is processed and formed by a photolithography method and a dry etching method. The first wiring 17 is formed.

  Thereafter, a second interlayer insulating film 16 is formed on the first interlayer insulating film 22 and the first wiring 17 by a CVD method. Thereafter, holes are formed in the second interlayer insulating film 16. Next, a metal film is formed in this hole and on the second interlayer insulating film 16 by a sputtering method, and then the metal film on the second interlayer insulating film 16 is removed by a CMP method. As a result, a second plug 18 electrically connected to the first wiring 17 is formed in the second interlayer insulating film 16. Thereafter, a wiring layer is formed on the second interlayer insulating film 16 and the second plug 18 by a sputtering method, and this wiring layer is processed and formed by a photolithography method and a dry etching method. The second wiring 20 is formed.

  Thereafter, a third interlayer insulating film 19 is formed on the second interlayer insulating film 16 and the second wiring 20 by a CVD method. Thereafter, holes are formed in the third interlayer insulating film 19. Next, a metal film is formed in the hole and on the third interlayer insulating film 19 by a sputtering method, and then the metal film on the third interlayer insulating film 19 is removed by a CMP method. As a result, a third plug 21 electrically connected to the second wiring 20 is formed in the third interlayer insulating film 19.

  Thereafter, the fine needle 1a shown in FIG. 1B is brought into contact with the third plug 21 electrically connected to the second wiring 20, and the electrical characteristics are obtained by a tester (not shown) connected to the fine needle 1a. Electrical characteristics are evaluated by inputting an evaluation signal to the transistor.

  As described above, according to the embodiment of the present invention, ion beam irradiation with gallium ions is performed on the surface of the fine needle 1a to remove the natural oxide film 2a attached to the surface of the fine needle 1a, and gallium and A surface layer 3a containing tungsten is formed. As a result, the value and variation of the contact resistance are greatly reduced, and a natural oxide film is hardly generated, and the state in which the value and variation of the contact resistance are greatly reduced can be maintained for a long time.

  Further, when the method of coating the metal film on which the natural oxide film is difficult to adhere to the tip surface of the fine needle, the tip diameter of the fine needle becomes thick, whereas in the present embodiment, the tip of the fine needle 1a. There is also an advantage that the diameter is hardly changed.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, a method for manufacturing a semiconductor device including a step of performing the above-described electrical property evaluation method is also included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1a ... Fine needle, 1b ... Tungsten, 2a, 2b ... Natural oxide film, 3a ... Surface layer, 4 ... Gallium ion, 30 ... Insulating film, 31 ... Al film 32 ... W plug, 10 ... silicon substrate, 11 ... LOCOS oxide film, 12 ... gate insulating film, 13 ... gate electrode, 24 ... LDD region diffusion layer, ..Diffusion layer in source / drain region, 14... Sidewall, 22... First interlayer insulating film, 15... First plug, 17. Second interlayer insulating film, 18 ... second plug, 20 ... second wiring, 19 ... third interlayer insulating film, 21 ... third plug

Claims (6)

A metal needle,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
A fine needle characterized by comprising:   2. The fine needle according to claim 1, wherein the diameter of the needle is 10 [mu] m or less.   3. The metal according to claim 1, wherein the metal is tungsten.   By irradiating the tip of a metal needle with an ion beam of gallium ion, argon ion, iodine ion, or cesium ion, a surface layer containing gallium, argon, iodine, or cesium is formed at the tip of the needle. A method for producing fine needles. An electrical property evaluation method comprising a step of contacting a semiconductor device or an electrode electrically connected to the semiconductor device with a fine needle and inputting a signal to the semiconductor device or the electrode through the fine needle to evaluate the electrical property. Because
The fine needle is
A metal needle,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
An electrical property evaluation method comprising: Manufacturing of a semiconductor device comprising a step of bringing a fine needle into contact with a semiconductor device or an electrode electrically connected to the semiconductor device, and inputting a signal to the semiconductor device or the electrode through the fine needle to evaluate electric characteristics A method,
The fine needle is
A metal needle,
A surface layer containing gallium or argon or iodine or cesium formed at the tip of the needle;
A method for manufacturing a semiconductor device, comprising:

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