JP5228586B2 - Vapor deposition mask, vapor deposition pattern production method using the same, semiconductor wafer evaluation sample production method, semiconductor wafer evaluation method, and semiconductor wafer production method - Google Patents

Description

The present invention relates to a vapor deposition mask for producing a vapor deposition pattern. More specifically, the present invention relates to a deposition mask suitable for forming a metal electrode on the surface of a wafer in order to measure electrical characteristics, particularly capacitance-voltage characteristics, at an arbitrary position of a semiconductor wafer with high accuracy.
Furthermore, the present invention relates to a deposition pattern manufacturing method using the mask, a semiconductor wafer evaluation sample manufacturing method, a semiconductor wafer evaluation method, and a semiconductor wafer manufacturing method.

  As a method for evaluating the quality of a silicon semiconductor wafer, there is a method of obtaining a wafer resistivity by forming a Schottky electrode by a metal electrode and measuring a capacitance-voltage characteristic of the Schottky electrode.

  As a method for forming a Schottky electrode, a method is known in which a metal film is formed on the entire wafer surface side, and an electrode pattern having a predetermined area is produced by photolithography. However, when photolithography is used, there is a problem that it takes time because it requires processes such as pattern exposure, cleaning, and rinsing.

Further, as a method for forming the Schottky electrode, a method called a vacuum vapor deposition method is also widely used. In the vacuum evaporation method, a metal is evaporated by resistance heating or electron irradiation in a vacuum, and the metal film is deposited on an object to be evaporated. At this time, in order to form an electrode having a predetermined area, a metal mask having a hole having a predetermined area is usually adhered to the wafer surface using a magnet (see, for example, Patent Documents 1 and 2). ).
JP 2001-003155 A JP-A-11-158605

  Generally used vacuum vapor deposition apparatuses are those using a resistance heating method or using an electron beam, and these usually have one vapor deposition source. FIG. 1 shows a schematic view of a general vacuum deposition apparatus. In a generally used vacuum vapor deposition apparatus, a wafer is fixedly arranged as shown in FIG. 1 (fixed type apparatus). The stationary apparatus is preferable in terms of work efficiency because the chamber can be downsized and the time required for evacuation can be shortened. However, in the fixed type apparatus, an electrode having an electrode area equivalent to the hole area can be formed without shadowing the hole portion directly under the vapor deposition source, but the mask is not provided in a portion away from the vapor deposition source, that is, the wafer outer peripheral portion. Shade by thickness is possible. This point will be further described below with reference to the drawings.

FIG. 2 shows a case in which a vapor deposition film is formed in a mask opening located directly under the vapor deposition source (FIG. 2A) and a case in which a vapor deposition film is formed in a mask opening located in a location away from the vapor deposition source (FIG. 2). The schematic diagram of the vapor deposition film formation state of (b)) is shown. FIG. 3 shows an enlarged schematic view of the vicinity of the hole in the embodiment shown in FIG. FIG. 4 shows an explanatory diagram of the influence of residual gas and moisture on the vapor deposition flow.
In a fixed type apparatus having one vapor deposition source as shown in FIG. 1, the vapor deposition source portion is heated by resistance heating, and the metal lump is evaporated. If the inside of the chamber is a vacuum, most of the vapor deposition flow generated by the evaporation of the metal mass goes straight and diffuses in a spherical shape. Therefore, as shown in FIG. 2 (a), the vapor deposition flow comes from directly above the vapor deposition source, so the hole cannot be shaded, whereas the part away from the vapor deposition source (wafer outer periphery) as shown in FIG. 2 (b). Part), the deposition flow comes diagonally, so the shadow is formed by the thickness of the hole. In this shaded area, as shown in FIG. 3, collisions between the molecules of the vapor deposition flow and collisions between molecules and residual air molecules occur, and vapor deposition molecules whose traveling direction has changed accumulate in the shaded part, so that a vapor deposition film is formed. The part which is not done and the part where thickness is not uniform occur. Moreover, although it is in a vacuum, the vapor deposition flow may change in the flying direction due to the remaining gas or water component, and may be deposited in the shaded area (see FIG. 4).
In general, in the method of evaluating the electrical characteristics of a semiconductor wafer by forming a Schottky electrode, after measuring the capacitance-voltage characteristics of a Schottky junction, the electrode pattern area is input to analysis software to determine the resistivity of the wafer. . In order to measure the area of the electrode formed by vapor deposition, an optical device (laser microscope, microscope equipped with a CCD camera, etc.) is usually used. However, there is a high possibility that the area where there is no contrast between the wafer surface and the deposited part or the shadow part is very small is not recognized as a deposited part by the above measuring device even though it acts as an electrode. May cause an error in resistivity.

  The shaded area becomes smaller as the mask thickness decreases. Therefore, it is conceivable to solve the above problem by reducing the thickness of a metal mask that has been used conventionally. However, when the metal material becomes thin, it becomes a metal foil shape, which makes it difficult to handle as a mask, such as being unable to be placed in close contact with a wafer by a magnet. By depositing a metal film on the entire wafer surface in advance and using photolithography, an electrode having a desired area without shadow can be formed. However, when a metal mask is used, electrical measurement can be performed immediately after vapor deposition, whereas when photolithography is used, processes such as pattern exposure, cleaning, and rinsing are required, which takes time.

  In order to solve the above problem, it is also conceivable to use a vacuum deposition apparatus (rotary type apparatus) equipped with a mechanism for rotating a wafer installed in a chamber. However, the rotary type apparatus has a problem that the chamber becomes large and requires a long time for evacuation, so that the working efficiency is lowered. In addition, it is conceivable to provide the same number of vapor deposition sources as the mask holes and arrange the vapor deposition sources directly above each hole. However, if the number of vapor deposition sources is increased, the required power of the vapor deposition machine becomes the sum of the number of vapor deposition sources increased. Therefore, a large amount of cost is required with a large-scale electric circuit change work. Moreover, there is a problem that increasing the number of vapor deposition sources increases the consumption of the metal for vapor deposition and increases the cost.

  Accordingly, an object of the present invention is to provide means capable of easily and easily evaluating the electrical characteristics of a semiconductor wafer.

In order to avoid the above-described problem of shadowing during vapor deposition, it is conceivable to reduce the thickness of the metal mask to about several tens of microns. However, a magnetic metal mask with a thickness of several tens of microns is like a metal foil, so when using a magnet to adhere to the wafer surface, it is too soft and the mask itself is distorted, and there is a gap between the hole and the wafer surface due to the distortion. It is difficult to form an electrode that can be formed to have a desired area. In addition, since the non-magnetic metal mask is not affected by the magnet, it can be handled easily when it is placed on the wafer surface. It is difficult to form an electrode that creates a desired area by forming a gap on the wafer surface.
Therefore, as a result of intensive studies, the present inventors have reduced the thickness of the mask while maintaining adhesion by placing a magnetic material on the mask when placing an ultra-thin mask on the wafer surface. The inventors have found that this can be achieved and have completed the present invention.

That is, the above object was achieved by the following means.
[1] A deposition mask for forming a deposition pattern on a deposition surface of an object to be deposited,
Having a mask layer made of a nonmagnetic material having at least one through hole and a thickness of 1 μm or more and 50 μm or less,
The deposition object is a semiconductor wafer,
On the mask layer, having a magnetic body without blocking the through-holes of the mask layer,
The magnetic body is a magnetic layer having at least one through hole, and an opening is formed by matching or overlapping the through hole of the mask layer and the through hole of the magnetic layer,
The opening of the through hole of the magnetic layer is larger than the opening of the through hole of the mask layer,
The through hole of the mask layer has a tapered shape in which the opening widens toward the surface on the magnetic body side,
The opening of the through hole of the mask layer and the opening of the through hole of the magnetic layer are concentric .
Mask layer and the magnetic body are separate members,
The object to be deposited is placed on a holder, and a magnet is installed in the magnet installation groove in the holder.
The mask layer and the magnetic body are disposed on the deposition surface in the order of the mask layer and the magnetic body,
The mask layer and the magnetic body have alignment holes, and alignment is performed by inserting an alignment member of the holder into the holes at the time of the arrangement.
The vapor deposition mask , wherein the deposition object, the mask layer, and the magnetic body are fixed by the magnetic force of the magnet .
[2] The vapor deposition mask according to [1], wherein the magnetic material has a thickness of 100 μm or more and 1 mm or less.
[3] The evaporation mask according to [1] or [2], wherein the mask layer is a layer made of at least one selected from the group consisting of SUS304, aluminum, copper, and a resinous material.
[4] The evaporation mask according to any one of [1] to [3], wherein the magnetic body is at least one selected from the group consisting of SUS430, iron, and nickel.
[5] A vapor deposition pattern manufacturing method in which the vapor deposition mask according to any one of [1] to [4] is disposed on a vapor deposition surface of a vapor deposition object, and then vapor deposition treatment is performed on the vapor deposition surface,
The mask is disposed on the deposition object such that the deposition surface and the mask layer surface face each other; and
A vapor deposition pattern manufacturing method, comprising: arranging a magnet on a surface opposite to a surface on which the mask is disposed.
[6] The vapor deposition pattern manufacturing method according to [5], wherein the deposition target surface is a semiconductor wafer surface, and a metal pattern is formed on the semiconductor wafer surface by vapor deposition.
[7] A method for producing a semiconductor wafer evaluation sample, wherein a metal pattern is produced on a semiconductor wafer surface by the method according to [6].
[8] A metal pattern is formed on the surface of the semiconductor wafer by the method described in [6],
A semiconductor wafer evaluation method for measuring electrical characteristics of a semiconductor wafer through a produced metal pattern.
[9] preparing a lot of semiconductor wafers comprising a plurality of semiconductor wafers;
Extracting at least one semiconductor wafer from the lot;
Evaluating the quality of the extracted semiconductor wafer;
A method for manufacturing a semiconductor wafer, comprising shipping as a product wafer another semiconductor wafer in the same lot as the semiconductor wafer determined to be non-defective by the evaluation,
The method according to claim 8, wherein the evaluation of the extracted semiconductor wafer is performed by the method according to [8].

  According to the present invention, in a vacuum deposition apparatus having a small vacuum chamber, an electrode is repeatedly and accurately formed at an arbitrary position on the wafer surface without making a costly modification, and a shadow portion depending on the electrode thickness is formed. By making it smaller, variations in electrode area measurement in the area measuring apparatus can be suppressed. Thereby, according to this invention, the quality of semiconductor wafers, such as a silicon wafer, can be evaluated highly accurately and easily.

[Deposition mask]
The vapor deposition mask of the present invention is a vapor deposition mask for forming a vapor deposition pattern on a surface to be vapor-deposited, and has a mask layer having at least one through hole and a thickness of 1 μm to 50 μm, and the mask layer On the top, the magnetic layer is provided without blocking the through hole of the mask layer.

Conventionally, when a metal material that has been used as a mask material has a thickness of about several tens of microns, it becomes difficult to place the metal material on a wafer by a magnetic force or the like because it becomes like a metal foil. Therefore, considering the ease of handling as a mask, it is required to have a thickness exceeding 100 μm. However, if the thickness exceeds 100 μm, there is a possibility that the measurement accuracy may be reduced due to the above-described shadow area.
Therefore, in the present invention, the thickness of the mask (mask layer) is 1 μm or more and 50 μm or less. However, in the case of a magnetic metal material, when it becomes the above thickness, it becomes like a metal foil, so that it cannot be placed so as to cover the wafer surface and it is difficult to make it adhere by magnetic force. Although non-magnetic metal materials and resin materials are usually relatively rigid or flexible even if they have the above-mentioned thickness, they can be mounted so as to cover the wafer surface itself, but they are adhered by magnetic force. I can't let you.
Therefore, in the present invention, a magnetic material is disposed on the mask layer, and the mask layer is brought into close contact with the wafer surface by the magnetic force of the magnetic material. As a result, it is possible for evaluation to be performed with high accuracy by using a stationary type vapor deposition device that is advantageous in terms of work efficiency compared to a rotary type vapor deposition device, avoiding a decrease in measurement accuracy due to the shaded area. A sample can be made.
Hereinafter, the vapor deposition mask of the present invention will be described in more detail.

  The vapor deposition mask of the present invention has a mask layer having at least one through hole and a thickness of 1 μm to 50 μm. If the thickness of the mask layer is less than 1 μm, handling is difficult and workability is reduced. When the thickness exceeds 50 μm, a measurement error due to the above-described shadow portion occurs, and it is difficult to make it adhere to the deposition surface by being sandwiched between the magnetic body and the magnet. The thickness of the mask layer is preferably in the range of 5 to 45 μm, more preferably 10 to 40 μm.

  The mask layer may be a metal material or a resinous material. The metal material may be a magnetic metal material or a non-magnetic metal material, but the magnetic metal material is like a metal foil at the above thickness and is inferior in workability. Therefore, it is preferable to use a non-magnetic metal material. . The “metal” in the present invention includes an alloy of two or more metals. Examples of preferable nonmagnetic metal materials include SUS304, aluminum, and copper. Further, as the resinous material, it is preferable to use a heat resistant resin that does not change even at the temperature during the vapor deposition treatment. Examples of the resin having heat resistance include a fluorine resin (for example, polytetrafluoroethylene), a polyolefin resin (for example, polyethylene), and a polyimide resin. The heat resistance means that deformation does not occur even at a temperature of 100 ° C. or higher, for example.

  The mask layer has at least one through hole. The number of through-holes is at least one and is not particularly limited, and may be set according to the use of the deposition surface. The size of the through hole may be approximately the same as the size of each vapor deposition pattern to be formed, and may be about 1 to 3 mm in diameter, for example. In the case of a through-hole having a tapered opening described later, the size of the vapor deposition pattern to be formed and the size of the through-hole opening on the vapor deposition surface side surface of the mask layer may be substantially the same.

  The through hole of the mask layer may be tapered so that the opening becomes wider toward the surface on the magnetic material side. The taper angle is preferably smaller than an acute angle formed by a straight line parallel to the pattern formation surface and a straight line connecting the vapor deposition source and the pattern formation position, based on the relationship between the vapor deposition source and the pattern formation position.

  The vapor deposition mask of the present invention has a magnetic material on the mask layer without blocking the through holes of the mask layer. An example of the arrangement of the magnetic material on the mask layer is shown in FIG. In the vapor deposition mask of the present invention, as shown in the upper diagram of FIG. 5, a magnetic material may be partially disposed on the mask layer so as not to block the through-holes of the mask layer. Thus, a mask having a two-layer structure in which two layers of magnetic layers (magnetic masks) having the same shape as the mask layer are stacked may be used. In this case, the opening of the vapor deposition mask is formed by matching or overlapping the two-layer through-holes.

Below, with reference to FIG. 6, an example of the work flow which installs a two-layer mask on a vapor deposition surface is demonstrated taking the example that the vapor deposition thing is a semiconductor wafer.
First, the wafer is placed on a wafer holder on which a magnet is installed (1 in FIG. 6).
Next, the mask 1 having the above-described thickness having the holes 1 at a predetermined position where the deposition pattern is to be formed on the entire wafer surface is placed (2 in FIG. 6). In this state, the mask 1 has poor adhesion to the wafer surface, so that there are gaps in some places. Since there is a gap in the hole portion, the vapor deposition film enters the gap portion and becomes distorted with respect to the shape to be formed, and accurate area measurement cannot be performed. Further, the portion where the deposited film enters is also an unclear portion whether or not it acts as an electrode. In order to eliminate this gap, a magnetic mask 2 is further placed on the mask 1 (3 in FIG. 6). Due to the attractive force of the magnetic mask 2 and the magnet of the holder below the wafer, the adhesion between the mask 1 and the wafer surface is improved, and the gap between the wafer surface and the mask 1 is eliminated. Thereby, there is no gap between the hole portions, and an electrode having a desired electrode area can be formed.

  The magnetic body is preferably a magnetic metal material. In the present invention, “magnetic” means a property attracted by a magnet, and a substance having the property is called a magnetic substance. Examples of the magnetic metal material include SUS430, iron, nickel, and the like.

  The thickness of the magnetic layer is preferably 100 μm or more from the viewpoint of improving the adhesion between the mask layer and the deposition surface. The upper limit of the thickness is not particularly limited, but is preferably 1 mm or less from the viewpoint of workability. The thickness of the magnetic body is preferably in the range of 100 μm to 300 μm.

  The through hole of the magnetic layer may be the same as or overlapping with the through hole of the mask so that the open state of the through hole is maintained even when the magnetic layer is disposed on the mask layer. It is preferable that it is larger than the opening of the through-hole which has. For example, when each opening is circular, the diameter of the through hole of the magnetic layer is preferably larger than the diameter of the through hole of the mask layer. As described above, when the through hole of the mask layer is tapered, it is preferable that the through hole opening of the magnetic layer is larger than the magnetic layer side opening of the mask layer. More specifically, it is preferable to arrange the magnetic layer so that the hole edge of the magnetic layer is located so as not to block the line connecting the edge of the mask layer hole on the magnetic layer side and the evaporation source with a straight line. Furthermore, it is preferable that the opening of the through hole of the mask layer and the opening of the through hole of the magnetic layer are concentric, because both layers can be easily stacked while maintaining the opening.

  As described above, the through hole of the mask layer is preferably tapered so that the opening becomes wider toward the surface on the magnetic body side. When the magnetic layer is arranged on the mask layer having such a tapered through hole, the opening of the magnetic layer can be tapered so that the opening becomes wider toward the surface opposite to the mask layer.

  The mask layer and the magnetic layer can be produced by a known mask forming method. In the present invention, since the deposition object, the mask layer, and the magnetic layer can be fixed by magnetic force, it is not necessary to bond the mask layer and the magnetic body with an adhesive. As shown in the examples described later, alignment holes can be provided in both layers, and alignment can be performed by inserting an alignment member of a holder for placing the deposition target into the alignment holes.

  In the vapor deposition mask of the present invention described above, each of the mask layer and the magnetic layer may have a single layer structure or a laminated structure of two or more layers. In the case of a laminated structure, the materials of the plurality of layers included are not necessarily the same. In the case of a laminated structure, the thickness of the mask layer and the thickness of the magnetic layer (magnetic material) are the total thickness of the laminated layers.

[Vapor deposition pattern production method]
Furthermore, this invention relates to the vapor deposition pattern preparation method which arrange | positions the vapor deposition mask of this invention on the vapor deposition surface of a to-be-deposited object, and then vapor-deposits on the vapor deposition surface. In the vapor deposition pattern manufacturing method of the present invention, the mask is disposed on the vapor deposition target so that the vapor deposition surface and the mask layer surface face each other, and a magnet is disposed on the surface opposite to the surface on which the mask is disposed. Place. As a result, the mask layer can be brought into close contact with the deposition surface by the magnetic force of the magnetic layer and the magnet, and a deposition pattern can be formed on the deposition surface via the thin mask layer.

  The said magnet is arrange | positioned on the surface opposite to the surface which has arrange | positioned the mask of to-be-deposited object. The magnet can be disposed on the entire surface of one of the deposition surfaces, or can be partially disposed. As shown in the examples described later, it is preferable to provide a magnet-installing groove in the holder for installing the deposition object, and to dispose the magnet in the groove. The number, shape, and magnetic force of the magnets to be arranged are not particularly limited, and may be set as appropriate so that the thin mask layer can be fixed on the deposition surface by the magnetic force.

  As a vapor deposition apparatus used for the vapor deposition process, a commonly used vacuum vapor deposition apparatus can be used without any limitation. As a vacuum vapor deposition apparatus that can be used in the present invention, a resistance heating type apparatus as shown in FIG. 1 can be exemplified. In such a resistance heating type apparatus, a vapor deposition film is formed by heating a vapor deposition source part by resistance heating and evaporating a vapor deposition material so that the vapor deposition flow advances in a spherical shape and deposits on the deposition target.

  As described above, the vapor deposition apparatus includes a rotary vapor deposition apparatus and a fixed vapor deposition apparatus, and any of the vapor deposition pattern manufacturing methods of the present invention can be used. Further, the apparatus may be a single deposition source or a plurality of deposition sources in the chamber. Since the mask for vapor deposition of the present invention has a thin mask layer as described above, a vapor deposition pattern can be produced without causing a problem due to the mask thickness even when a single vapor deposition source is used. Can do.

  The vapor deposition source used for vapor deposition is selected according to the purpose. For example, when a metal electrode is formed on the wafer surface for preparing a sample for evaluation of a semiconductor wafer, gold, aluminum, antimony, or the like is used. Can do. Moreover, the vapor deposition process conditions in the vapor deposition pattern production method of the present invention may be appropriately set in consideration of the thickness and size of the desired vapor deposition pattern.

  Examples of the target for producing the vapor deposition pattern by the vapor deposition pattern production method of the present invention include various surfaces that are usually subjected to vapor deposition treatment, but a semiconductor wafer is suitable. Details of the semiconductor wafer will be described later. A Schottky electrode is formed by forming a metal pattern on a semiconductor wafer, and a space charge density [(donor concentration) − (acceptor concentration)] is determined from the capacitance-voltage characteristics of the Schottky junction. The resistivity of the wafer can be obtained from the area. The electrode area is usually measured by an optical device. However, as described above, when it is difficult to obtain an accurate electrode area due to the wafer thickness, a measurement error occurs and an accurate measurement value cannot be obtained. On the other hand, according to the vapor deposition mask of the present invention, it is possible to measure an accurate electrode area with an optical device, and thereby, the resistivity of the wafer can be obtained with high accuracy.

  After the vapor deposition treatment, the surface on which the vapor deposition pattern is formed can be obtained by removing the entire vapor deposition mask from the deposition surface.

[Method for preparing semiconductor wafer evaluation sample]
Furthermore, the present invention relates to a method for producing a semiconductor wafer evaluation sample in which a metal pattern is produced on the surface of a semiconductor wafer by the vapor deposition pattern production method of the present invention.
The semiconductor wafer evaluation sample can be, for example, a sample used for obtaining the resistivity of the semiconductor wafer from the capacitance-voltage characteristics of the Schottky junction as described above. Examples of the semiconductor wafer for producing the metal pattern (metal electrode) include a silicon epitaxial wafer and a mirror polished wafer. The formed semiconductor wafer evaluation sample can be used in the semiconductor wafer evaluation method of the present invention. Details thereof will be described later.

[Semiconductor wafer evaluation method]
The semiconductor wafer evaluation method of the present invention is a method in which a metal pattern is produced on a semiconductor wafer by the vapor deposition pattern production method of the present invention, and the electrical characteristics of the semiconductor wafer are measured through the produced metal pattern. The electrical characteristics measured here include the resistivity of the semiconductor wafer. The resistivity of the semiconductor wafer can be obtained by the method (CV method) for measuring the capacitance-voltage characteristics of the Schottky junction as described above. Measurements can be made after the vapor deposition mask has been peeled from the wafer.

[Semiconductor wafer manufacturing method]
The method of manufacturing a semiconductor wafer according to the present invention includes a step of preparing a lot of semiconductor wafers composed of a plurality of semiconductor wafers, a step of extracting at least one semiconductor wafer from the lot, and evaluating the quality of the extracted semiconductor wafer. And a step of shipping another semiconductor wafer in the same lot as the semiconductor wafer determined to be non-defective by the evaluation, and evaluating the extracted semiconductor wafer as an evaluation of the semiconductor wafer of the present invention. It is done by the method.

  According to the semiconductor wafer evaluation method of the present invention, the electrical characteristics of the wafer can be evaluated with high accuracy. Therefore, it is possible to provide a high-quality semiconductor wafer by selecting a semiconductor wafer of the same lot as the silicon wafer that has been confirmed to have a quality exceeding the target by the evaluation and shipping it as a product wafer. In addition, the reference | standard determined as a good product can be set in consideration of the physical property calculated | required by the wafer according to the use etc. of a wafer. The number of wafers extracted for evaluation may be at least one, and by setting it to two or more, it becomes possible to ship products with high reliability. The preparation of semiconductor wafer lots can be performed by a known method, and the number of wafers contained in one lot may be determined in consideration of productivity and the like.

  Below, the present invention will be further explained based on examples. However, this invention is not limited to the aspect shown in the Example.

[Example 1]
FIG. 7 shows a plan view of a magnetic metal mask (SUS430) having a thickness of 100 μm, a nonmagnetic metal mask (SUS304) having a thickness of 40 μm, and a holder. The hole size of the magnetic metal mask was 5 mmφ, and the hole size of the nonmagnetic metal mask was 3 mmφ. The through hole of the nonmagnetic mask had a tapered shape with an opening widened toward the magnetic mask side, and the thickness on the side in contact with the wafer surface was 15 μm. The holder has a number of grooves in the surface for installing magnets. Magnets were installed in these grooves. The thickness of the magnet was substantially the same as the groove depth so that the holder surface was not uneven when the magnet was installed. The magnetic force can be adjusted depending on the number of magnets to be arranged and the arrangement position.
A wafer (6 inches, n-type, (100), resistivity 6 Ωcm), which is a deposition object, was placed on the holder, and then the mask was placed on the wafer. A schematic cross-sectional view of this state is shown in FIG.
Thereafter, the silicon wafer with a mask was placed in a vacuum deposition apparatus together with a holder to perform a deposition process. The resistance heating type (fixed type) apparatus shown in FIG. 1 was used as the vacuum deposition apparatus. The resistance heating filament was a tungsten filament, the deposited metal was gold, and the distance between the filament and the wafer was 20 cm. The electrode area after the vapor deposition treatment was measured at 5 points in the diameter direction (5 mm from the outer periphery, R / 2, center) using a NIKOON confocal laser microscope NEXIV. Further, the mask was removed after the vapor deposition treatment, and the capacitance-voltage characteristics of the formed electrode were measured. The electrode area measured by the confocal laser microscope was input to the analysis software, and the resistivity was obtained. For each resistivity measurement, the metal electrode was peeled and removed with chemicals, and the operations of electrode formation, electrode area measurement, and resistivity measurement were repeated five times. Capacitance-voltage measurement was performed using Agilent 4284A, and conversion to resistivity followed the SEMI equation. 9 shows variation in electrode area measurement, and FIG. 10 shows variation in resistivity value.

[Comparative Example 1]
Measurement variation in electrode area measurement and resistivity value in the same manner as in Example 1 except that a magnetic metal mask having a thickness of 100 μm and having an opening at the same position as in the mask of Example 1 was used. The variation of was calculated. 9 shows variation in electrode area measurement, and FIG. 10 shows variation in resistivity value.

  9 and 10, CV values (relative standard deviations) are calculated from the average value and standard deviation obtained by performing the measurement five times at each point. The result of relative comparison of the values is shown. The larger the value, the greater the variation. As shown in FIG. 9, the electrode formed in Example 1 showed little variation at any electrode position, whereas the electrode formed in Comparative Example 1 showed larger variation as it moved away from the center. This is because the deposition source is arranged almost directly above the center of the wafer, and the shadow portion increases as the distance from the center of the wafer increases. Thus, the variation in the electrode area causes a measurement error in the resistivity measurement. Therefore, as shown in FIG. 10, in the resistivity measurement in Example 1, there was almost no variation in resistivity depending on the position in the plane, whereas in the resistivity measurement in Comparative Example 1, the variation was more away from the center. Became larger.

  According to the present invention, the quality of a semiconductor wafer can be evaluated with high reliability. Further, according to the present invention, a highly reliable evaluation can be performed by a simple vapor deposition apparatus (a fixed vapor deposition apparatus having one vapor deposition source).

The schematic of a resistance heating type vacuum evaporation system is shown. When forming a vapor deposition film in a mask opening located directly under the vapor deposition source (FIG. 2A) and when forming a vapor deposition film in a mask opening located at a location away from the vapor deposition source (FIG. 2B) The schematic diagram of the vapor deposition film formation state of is shown. The expansion schematic diagram of the hole vicinity of the aspect shown in FIG.2 (b) is shown. It is explanatory drawing of the influence on the vapor deposition flow of residual gas and a water | moisture content. The example of arrangement | positioning of the magnetic body on a mask layer is shown. An example of the work flow which installs a two-layer mask on a to-be-deposited surface is shown. The top view of the magnetic body metal mask, nonmagnetic body metal mask, and holder which were used in Example 1 is shown. FIG. 3 is a schematic cross-sectional view illustrating an arrangement state of a wafer, a holder, and a mask in Example 1. The dispersion | variation in the electrode area measurement of Example 1 and Comparative Example 1 is shown. The resistivity value dispersion | variation measured by Example 1 and the comparative example is shown.

Claims (9)

A deposition mask for forming a deposition pattern on a deposition surface of an object to be deposited,
Having a mask layer made of a nonmagnetic material having at least one through hole and a thickness of 1 μm or more and 50 μm or less,
The deposition object is a semiconductor wafer,
On the mask layer, having a magnetic body without blocking the through-holes of the mask layer,
The magnetic body is a magnetic layer having at least one through hole, and an opening is formed by matching or overlapping the through hole of the mask layer and the through hole of the magnetic layer,
The opening of the through hole of the magnetic layer is larger than the opening of the through hole of the mask layer,
The through hole of the mask layer has a tapered shape in which the opening widens toward the surface on the magnetic body side,
The opening of the through hole of the mask layer and the opening of the through hole of the magnetic layer are concentric .
Mask layer and the magnetic body are separate members,
The object to be deposited is placed on a holder, and a magnet is installed in the magnet installation groove in the holder.
The mask layer and the magnetic body are disposed on the deposition surface in the order of the mask layer and the magnetic body,
The mask layer and the magnetic body have alignment holes, and alignment is performed by inserting an alignment member of the holder into the holes at the time of the arrangement.
The vapor deposition mask , wherein the deposition object, the mask layer, and the magnetic body are fixed by the magnetic force of the magnet . The deposition mask according to claim 1, wherein the magnetic body has a thickness of 100 μm to 1 mm. The mask for vapor deposition according to claim 1 or 2, wherein the mask layer is a layer made of at least one selected from the group consisting of SUS304, aluminum, copper, and a resinous material. The vapor deposition mask according to any one of claims 1 to 3, wherein the magnetic body is at least one selected from the group consisting of SUS430, iron and nickel. A vapor deposition pattern manufacturing method in which the vapor deposition mask according to any one of claims 1 to 4 is disposed on the vapor deposition surface of the vapor deposition object, and then vapor deposition treatment is performed on the vapor deposition surface,
The mask is disposed on the deposition object such that the deposition surface and the mask layer surface face each other; and
A vapor deposition pattern manufacturing method, comprising: arranging a magnet on a surface opposite to a surface on which the mask is disposed. The vapor deposition pattern manufacturing method according to claim 5, wherein the deposition surface is a semiconductor wafer surface, and a metal pattern is formed on the semiconductor wafer surface by vapor deposition. The manufacturing method of the sample for semiconductor wafer evaluation which produces a metal pattern on the semiconductor wafer surface by the method of Claim 6. A metal pattern is produced on a semiconductor wafer surface by the method according to claim 6,
A semiconductor wafer evaluation method for measuring electrical characteristics of a semiconductor wafer through a produced metal pattern. Preparing a lot of semiconductor wafers comprising a plurality of semiconductor wafers;
Extracting at least one semiconductor wafer from the lot;
Evaluating the quality of the extracted semiconductor wafer;
A method for manufacturing a semiconductor wafer, comprising shipping as a product wafer another semiconductor wafer in the same lot as the semiconductor wafer determined to be non-defective by the evaluation,
9. The method according to claim 8, wherein the evaluation of the extracted semiconductor wafer is performed by the method according to claim 8.