JP2006294814A - Method of forming through-electrode on substrate, and manufacturing method of semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably form a through-electrode with no variation in conductivity, and to provide a method for forming the through-electrode at a low cost. <P>SOLUTION: A conductive material of a volume smaller than that of a non-through hole is supplied to a surface on one side in the thickness direction of a substrate comprising the non-through hole, so that the opening of the non-through hole is closed. Thus, pressure in a space outside the non-through hole is higher than that in the non-through hole. Differential pressure between the inside and outside of the non-through hole allows the non-through hole to be packed with the conductive material. A packing operation is repeated until the non-through hole is filled with the conductive material. The other surface of the substrate is recessed until the conductive material is exposed to the outside to stably form the through-electrode with no variation in conductivity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for forming a through electrode on a substrate and a method for manufacturing a semiconductor device using the same.

  With the miniaturization of electronic devices such as mobile phones, stacked semiconductor modules are used in electronic devices. A stacked semiconductor module is configured by stacking semiconductor devices. In the stacked semiconductor module, it is necessary to electrically connect the stacked semiconductor devices. In order to electrically connect each semiconductor device, a through electrode is formed on, for example, a semiconductor substrate on which each semiconductor device is formed.

  FIG. 6 is a cross-sectional view of the semiconductor substrate 61 on which the through electrode is formed. The semiconductor substrate 61 is made of a silicon wafer, and a through-hole penetrating in the thickness direction of the semiconductor substrate 61 is formed. An insulating film 62 made of a silicon oxide film is formed on the surface portion of the semiconductor substrate 61 and the inner wall of the through hole. The through electrode 63 is formed by filling a through hole penetrating in the thickness direction of the semiconductor substrate 61 with a conductive material and curing the conductive material. The conductive material includes a metal having conductivity and a reactive diluent.

  FIG. 7 is a cross-sectional view of the semiconductor substrate 61 provided with wirings and through electrodes. A conductive cap wiring 66 is provided in contact with the through electrode 63 of the semiconductor substrate 61 on which the through electrode 63 shown in FIG. A semiconductor device formed by the semiconductor substrate 61 provided with such a cap wiring 66 and the through electrode 63 can be stacked to form a stacked semiconductor module.

  FIG. 8 is a diagram for explaining a method of forming the through electrode 63 on the semiconductor substrate 61 using the first conventional technique. In the first conventional technique, the through electrode 63 of the semiconductor substrate 61 is formed by the following procedure. First, as shown in FIG. 8A, a non-through hole 64 is formed in the semiconductor substrate 61 so as to open at the surface portion on one side in the thickness direction and to be blocked by the surface portion on the other side in the thickness direction. Next, as shown in FIG. 8B, after the insulating film 62 is formed on the inner wall of the semiconductor substrate 61 in the non-through hole 64, the non-through hole 64 is filled with a conductive material, the conductive material is cured, and the embedded electrode 65 is filled. Form. Thereafter, the surface portion on the other side in the thickness direction of the semiconductor substrate 61 is mechanically ground, so that the embedded electrode 65 is removed from both surface portions in the thickness direction of the semiconductor substrate 61 as shown in FIG. A through electrode 63 is formed on the semiconductor substrate 61.

  Here, when filling the non-through hole 64 with the conductive material, in the first conventional technique, the conductive material applied to the surface portion of the semiconductor substrate 61 is opened in the non-through hole 64 by a squeegee in a vacuum atmosphere. Printing is performed on the surface portion of the semiconductor substrate 61 so as to close the portion. Next, by adjusting the vacuum atmosphere to an atmospheric pressure atmosphere, a differential pressure is generated between the pressure inside the non-through hole 64 and the pressure outside the non-through hole 64, and the differential pressure inside and outside the non-through hole 64 The non-through hole 64 is filled with a conductive material (see, for example, Patent Document 1).

  As a second conventional technique, there is a through electrode forming method using a technique similar to the first conventional technique. FIG. 9 is a flowchart showing an operation of filling a non-through hole with a conductive material according to the second prior art. In step B1, a non-through hole is formed that opens at one surface portion in the thickness direction of the semiconductor substrate and is closed by the other surface in the thickness direction. In step B2, an insulating film is formed on the inner wall of the semiconductor substrate in the non-through hole. In step B3, a conductive material is applied to the surface portion of the semiconductor substrate. In step B4, the conductive material applied to the surface portion of the semiconductor substrate is printed on the surface portion of the semiconductor substrate in a vacuum atmosphere, and the openings of the non-through holes are closed with the conductive material. In Step B5, the conductive material is filled in the non-through holes by returning the vacuum atmosphere to an atmospheric pressure atmosphere. In step B6, the conductive material is further printed on the surface portion using a squeegee under atmospheric pressure, and the non-through hole is filled with the conductive material by the printing pressure generated during printing. In step B7, the filling is completed, and the filling operation is finished. By curing the conductive material filled in the non-through holes, the embedded electrode is formed and the through electrode is formed (for example, see Patent Document 2).

  Furthermore, as a third conventional technique, as in the first and second conventional techniques, after filling a non-through hole with a conductive material by differential pressure, a liquid conductive substance is further formed by electroless plating. There is a method of filling a non-through hole, forming a buried electrode, and forming a through electrode (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 2001-127087 JP 2003-257891 A Japanese Patent No. 339789

  In the first and second conventional techniques, the non-through hole is filled with an amount of the conductive material equal to or larger than the volume of the non-through hole at a time. Therefore, the conductive material may not be filled up to the bottom in the non-through hole. When the conductive material is not filled up to the bottom of the non-through hole and the conductive material is cured and the through electrode is formed, a void is formed in the through electrode. A through electrode having a void formed therein has a higher resistance value than a through electrode formed by uniformly filling a conductive material. When the stacked semiconductor device is formed by electrically connecting the semiconductor devices using the through electrodes having variations in conductivity as described above, there is a problem that the yield of the stacked semiconductor device is lowered.

  Further, in the first and second conventional techniques, in order to fill the bottom of the non-through hole with the same amount of conductive material as the volume of the non-through hole, the differential pressure inside and outside the non-through hole is reduced. By enlarging and filling the non-through hole, the conductive material tends to spread on the surface of the semiconductor substrate 61 around the non-through hole opening. When the conductive material spreads on the surface portion of the semiconductor substrate, bleeding of the reactive diluent contained in the conductive material occurs on the surface portion of the semiconductor substrate 61. When semiconductor chips are stacked using a semiconductor substrate in which bleeding of the reactive diluent occurs on the surface portion, there is a problem that the yield of the semiconductor device is reduced.

  The method described in Patent Document 3 is a method in which a liquid conductive material is filled in a void formed in the through electrode by an electroless plating method. There is a problem that it is necessary to use a substance, and the number of steps increases, resulting in an increase in cost.

  An object of the present invention is to fill a conductive material without forming a void in a non-through hole, prevent the conductive material from spreading on the surface of the substrate, and stably form a through electrode without variation in conductivity. At the same time, it is to provide a method for forming a through electrode at a low cost.

The present invention provides a non-through hole forming step for forming a non-through hole in the substrate, which is opened at the surface portion on one side in the thickness direction and closed at the surface portion on the other side in the thickness direction;
An insulating film forming step of forming an insulating film on the inner wall of the substrate in the non-through hole;
A conductive material having a volume smaller than the volume of the non-through hole is supplied to the surface portion on one side in the thickness direction of the substrate to close the opening of the non-through hole, Filling the conductive material by repeating the filling operation of filling the non-through hole with the conductive material by making the pressure in the space higher than the pressure of the non-through hole and filling the non-through hole with the differential pressure inside and outside the non-through hole. Process,
And a through hole forming step of retracting the other surface of the substrate until the conductive material is exposed to the outside.

  According to the present invention, the substrate is formed with a non-through hole that opens at the surface portion on one side in the thickness direction and is blocked by the surface portion on the other side in the thickness direction, and an insulating film is formed on the inner wall of the substrate in the non-through hole To do. Thereafter, a conductive material having a volume smaller than the volume of the non-through hole is supplied to the surface portion on one side in the thickness direction of the substrate to close the opening of the non-through hole. The pressure in the outer space is made higher than the pressure in the non-through hole, and the non-through hole is filled with the conductive material by the differential pressure inside and outside the non-through hole. Such a filling operation is repeated until the non-through hole is filled with the conductive material. When the non-through hole is filled with the conductive material, the other surface of the substrate is retracted until the conductive material is exposed to the outside, and the through hole is formed to form the through electrode on the substrate.

  In this way, the volume of the conductive material that fills the non-through hole in one filling operation is smaller than the volume of the non-through hole, so the non-through hole reaches the bottom of the non-through hole or until the previous filling operation. The conductive material can be reliably filled up to the surface portion on the opening side of the non-through hole in the filled conductive material. Therefore, since it is possible to prevent a void from being formed in the non-through hole already filled with the conductive material, it is possible to prevent a void from being formed in the through electrode formed by curing the conductive material. In addition, since the filling operation of the conductive material is repeated a plurality of times, even if a gap is formed in the non-through hole filled with the conductive material in the previous filling operation, The gap formed so far can be reduced or eliminated by the differential pressure inside and outside the non-through hole in the subsequent filling operation. Therefore, since the non-through holes can be filled with a conductive material with a uniform density, it is possible to stably form through electrodes that have no variation in conductivity.

  Further, according to the present invention, in the conductive material filling step, the differential pressure inside and outside the non-through hole in each filling operation is set so as to become smaller as the subsequent filling operation is performed as viewed throughout the conductive material filling step. And

  According to the present invention, the differential pressure inside and outside the non-through hole is set to be smaller as the subsequent filling operation is performed as viewed throughout the conductive material filling process. Therefore, the differential pressure adjustment time can be shortened compared to the case where the differential pressure equal to or greater than the differential pressure inside or outside the non-through hole in the first filling operation is adjusted in each filling operation. And the work in the filling operation becomes easy.

  Further, according to the present invention, the differential pressure inside and outside the non-through hole in at least one filling operation among the filling operations executed in the conductive material filling step is larger than the differential pressure inside and outside the non-through hole in the previous filling operation. It is set as follows.

  According to the present invention, at least once, the differential pressure inside and outside the non-through hole in the filling operation is set to be larger than the differential pressure inside and outside the non-through hole in the previous filling operation. In this way, the conductive material is newly filled with a differential pressure larger than the previous differential pressure. Therefore, even if a void is formed in the non-through hole that is already filled with the conductive material by the previous filling operation, the formed void can be surely eliminated or reduced. The non-through holes can be filled with a conductive material with a uniform density, and a through electrode without variation in conductivity can be stably formed.

  Further, in the conductive material filling step, the conductive material is supplied to the surface portion on one side in the thickness direction of the substrate in an atmosphere adjusted to a pressure lower than the atmospheric pressure in the conductive material filling step, and the opening of the non-through hole is blocked. The conductive material is filled in the non-through hole by returning the atmospheric pressure outside the non-through hole to atmospheric pressure.

  According to the present invention, the conductive material is filled into the non-through hole by returning the atmospheric pressure outside the non-through hole to the atmospheric pressure, so when supplying the conductive material to the surface portion of the substrate in the filling operation, When lowering the pressure of the ambient atmosphere and filling the non-through holes with the conductive material, it is only necessary to open the ambient atmosphere of the substrate to atmospheric pressure. Therefore, the work of filling the non-through holes with the conductive material is facilitated as compared with the case where the pressure of the ambient atmosphere around the substrate is adjusted when the conductive material is supplied to the surface portion of the substrate and when the non-through holes are filled.

  In the first filling operation, the conductive material is supplied to the surface portion on one side in the thickness direction of the substrate in an atmosphere adjusted to a pressure of 2 kPa or less in the first filling operation, and the pressure is increased to 7 kPa or more in the last filling operation. A conductive material is supplied to a surface portion on one side in the thickness direction of the substrate in an adjusted atmosphere.

  According to the present invention, in the first filling operation in the conductive material filling process, the pressure in the non-through hole is 2 kPa or less and the pressure in the space outside the non-through hole is atmospheric pressure. The conductive material can be reliably filled up to the bottom of the non-through hole by the pressure difference from the pressure in the hole. Therefore, since the conductive material is filled with a uniform density up to the bottom of the non-through hole, it is possible to stably form a through electrode without variation in conductivity. When the pressure in the non-through hole is larger than 2 kPa, a void is formed in the non-through hole filled with the conductive material.

  In the final filling operation, the pressure inside the non-through hole is 7 kPa or more, and the pressure outside the non-through hole is atmospheric pressure, so when filling the non-through hole with the conductive material, Can be prevented from spreading. When the pressure in the non-through hole is smaller than 7 kPa, the conductive material spreads on the surface portion of the semiconductor substrate 1 when the non-through hole is filled with the conductive material.

  Further, according to the present invention, in the conductive material filling process, as the supply amount of the conductive material to the surface portion on one side in the thickness direction of the substrate in each filling operation becomes the previous filling operation when viewed through the entire conductive material filling process. It is set so that it may become small.

  In the conductive material filling process, the supply amount of the conductive material to the surface portion on one side in the thickness direction of the substrate in each filling operation is set so as to become smaller as it becomes the previous filling operation when viewed through the entire conductive material filling process. Is done.

  According to the present invention, during the first filling operation in which the volume in the non-through holes not filled with the conductive material is the largest in the entire conductive material filling process, the supply amount of the conductive material on the surface portion of the substrate is minimized. The non-through hole is filled with a conductive material. Therefore, since the conductive material can be reliably filled to the bottom of the non-through hole, the conductive material can be filled into the non-through hole with a uniform density. Therefore, the through electrode having no variation in conductivity can be stably formed.

  In the conductive material filling step, the conductive material is supplied to the surface portion on one side in the thickness direction of the substrate using hole plate printing.

  According to the present invention, since the conductive material is supplied using the hole plate printing method, the conductive material can be supplied to the surface portion of the substrate at a low cost. Therefore, the cost for forming the through electrode on the substrate can be reduced.

Moreover, this invention is a manufacturing method of the semiconductor device using the formation method of the said penetration electrode.
According to the present invention, since the through electrode is formed in the semiconductor substrate 1 by filling the non-through holes with a conductive material at a uniform density, and the semiconductor device is manufactured using the semiconductor substrate 1, the manufactured semiconductor The yield of the apparatus can be improved.

  According to the present invention, since a non-through hole can be filled with a conductive material with a uniform density, it is possible to stably form a through electrode without variation in conductivity.

  Moreover, according to this invention, the time which an electrode material filling process requires can be shortened, and operation | work becomes easy.

  Further, according to the present invention, voids in the conductive material can be eliminated or reduced, so that the non-through holes can be filled with the conductive material at a uniform density, and the through electrode without variation in conductivity can be stabilized. Can be formed.

  Further, according to the present invention, the conductive material is filled in the non-through hole as compared with the case where the pressure of the ambient atmosphere of the substrate is adjusted when the conductive material is supplied to the surface portion of the substrate and when the non-through hole is filled. Work becomes easy.

  Further, according to the present invention, it is possible to stably form a through electrode having no variation in conductivity. Further, when the conductive material fills the non-through hole, it can be prevented from spreading near the surface portion of the substrate.

  In addition, according to the present invention, since the non-through holes can be filled with the conductive material with a uniform density, it is possible to stably form the through electrodes without variation in conductivity.

  Moreover, according to this invention, a conductive material can be supplied to the surface part of a board | substrate at low cost. Therefore, the cost for forming the through electrode on the substrate can be reduced.

  Further, according to the present invention, the through electrode is formed in the semiconductor substrate 1 by filling the non-through hole with the conductive material with a uniform density, and the semiconductor device is manufactured using the semiconductor substrate 1. The yield of semiconductor devices can be improved.

  FIG. 1 is a flowchart showing a through electrode forming method according to an embodiment of the present invention. FIG. 2 is a diagram showing an outline of a filling step in the through electrode forming method according to the embodiment of the present invention. FIG. 3 is a diagram showing in detail a filling step in the through electrode forming method according to the embodiment of the present invention. FIG. 4 is a graph showing the transition of the pressure of the atmosphere in the chamber in the filling step in the through electrode forming method according to the embodiment of the present invention. In FIG. 2, the resist mask and the surface electrode are omitted in order to prevent the drawing from becoming complicated.

  The semiconductor device includes a semiconductor substrate 1 and a circuit layer formed on a surface portion on one side in the thickness direction of the semiconductor substrate 1 (hereinafter sometimes referred to as “main surface portion”). The semiconductor substrate 1 is formed using, for example, a wafer having a diameter of 8 inches made of silicon (Si). The circuit layer is formed including, for example, an element and the surface electrode 12. When a semiconductor device is stacked to form a stacked semiconductor device, for example, a through electrode that electrically connects the stacked semiconductor devices is used. The through electrode is an electrode formed including silver, gold, copper, tin, and the like, and is provided in the semiconductor device so as to penetrate in the thickness direction of the semiconductor substrate 1. Hereinafter, a method for forming the through electrode according to the present embodiment will be described.

  The through electrode forming method in the present embodiment includes a non-through hole forming step, an insulating film forming step, a conductive material filling step, and a through hole forming step. In the non-through hole formation, for example, a non-through hole forming operation is performed. In the insulating film forming step, for example, an insulating film forming operation is performed. In the conductive material filling step, for example, a filling operation is performed. In the through hole forming step, for example, a through hole forming operation is performed. In the present embodiment, the conductive material 6 is filled into the non-through holes 2 in the conductive material filling step, for example, a stencil using a printing machine having a printing mask 4 and a squeegee 5 in which holes 10 penetrating in the thickness direction are formed. Perform by printing method.

  In the present embodiment, a circuit layer (not shown) is first formed on the semiconductor substrate 1, and when preparation for forming the through electrode is completed, the process proceeds to step A1 and the formation of the through electrode is started.

In step A1, a non-through hole forming operation for forming the non-through hole 2 in the semiconductor substrate 1 is performed. In step A <b> 1, a non-through hole 2 is formed that opens at the main surface portion 7 of the semiconductor substrate 1 and is blocked by the back surface portion 8 that is the surface portion opposite to the main surface portion 7. The non-through hole 2 is, for example, DRIE (Deep-
Reactive Ion Etching) method. The non-through hole 2 is formed, for example, so as to open on the inner surface of the surface electrode 12 of the main surface portion 7 of the semiconductor substrate 1 which is the opening position of the resist mask 11. In the present embodiment, the non-through hole 2 to be formed has, for example, a hole diameter D of 75 μm, and a depth L from the main surface portion 7 to the bottom surface portion 13 of the non-through hole 2 is 150 μm. The shape of the non-through hole 2 is, for example, a substantially cylindrical shape. In the present invention, the substantially cylindrical shape includes a cylindrical shape. When such a non-through hole 2 is formed in the semiconductor substrate 1, the process proceeds to step A2.

  In step A2, an insulating film forming operation is performed to form the insulating film 3 so as to cover the inner wall portion of the semiconductor substrate 1 in the non-through hole 2. In step A2, the insulating film 3 is formed by, for example, CVD (Chemical Vapor Deposition) method, stencil printing method, spray method or the like, and insulating film 3 such as silicon oxide film or silicon nitride film is formed in semiconductor substrate 1 in non-through hole 2. It is formed over the entire inner wall portion. When the insulating film 3 is formed, the process proceeds to Step A3.

  In step A3, a conductive material application operation for applying the conductive material 6 to the surface of the print mask 4 is performed. In step A3, the semiconductor substrate 1 is placed on the stage of the printing machine in the pressure-adjustable chamber so that the back surface portion 8 faces the stage, and is sucked and fixed to the stage. Further, alignment is performed so that the center of the opening 9 of the non-through hole 2 and the center of the hole 10 of the printing mask 4 substantially coincide. In the present embodiment, for example, a stencil obtained by applying nickel plating to a SUS plate having a thickness of 0.05 mm to a thickness of 0.01 mm is used as the printing mask 4. A conductive material 6 is applied to the surface of the printing mask 4 opposite to the surface facing the main surface portion 7 of the semiconductor substrate 1. In the present embodiment, the conductive material 6 is a conductive paste having a viscosity of 100 pa · sec containing, for example, a reactive diluent and silver. When the conductive material 6 is defoamed on the surface of the printing mask 4, the process proceeds to step A4.

  In step A4, a first working pressure adjustment operation is performed to adjust the atmosphere in the chamber to a predetermined first working pressure. When the atmosphere in the chamber is adjusted to the first working pressure, the process proceeds to step A5.

  In step A5, a printing operation for supplying the conductive material 6 to the main surface portion 7 of the semiconductor substrate 1 by a stencil printing method is performed. In step A5, the conductive material 6 having a volume smaller than the volume of the non-through holes 2 is supplied to the main surface portion 7 of the semiconductor substrate 1 by stencil printing in a chamber adjusted to the first working pressure. In the present embodiment, the squeegee 5 is slidably moved on the surface of the print mask 4 to move the conductive material 6 to the hole 10 of the print mask 4 as shown in FIG. Supply to the main surface portion 7 of the semiconductor substrate 1. At this time, since the center of the hole 10 of the printing mask 4 and the center of the opening 9 of the non-through hole 2 are aligned, as shown in FIG. The main surface portion 7 of the semiconductor substrate 1 is supplied so as to be in contact with the surface electrode 12 and the resist mask 11. Further, the conductive material 6 supplied to the main surface portion 7 of the semiconductor substrate 1 closes the opening 9 of the non-through hole 2 by surface tension. When the printing operation is completed, the process proceeds to step A6.

  In step A6, a second working pressure adjustment operation is performed in which the atmosphere in the chamber is adjusted to a second working pressure that is higher than the first working pressure adjusted in step A4. In step A6, when the atmosphere in the chamber is adjusted to a second working pressure that is higher than the first working pressure, the non-through hole 2 is closed by the conductive material 6, so that the non-through hole 2 Differential pressure occurs inside and outside. Since the pressure inside the non-through hole 2 is lower than the second working pressure, the conductive material 6 is filled into the non-through hole 2 by the differential pressure inside and outside the non-through hole 2 as shown in FIG. In step A6, the atmosphere in the chamber is adjusted to the second working pressure, and when the conductive material 6 supplied to the main surface portion 7 of the semiconductor substrate 1 in step A5 is filled in the non-through hole 2 in step A5, the process proceeds to step A7. move on.

  In step A7, it is determined whether or not the filling operation, which is the operation from steps A4 to A6, has been repeated a predetermined number of times, for example, n (n is an integer of 2 or more). As shown in FIG. 2C, the conductive material 6 is supplied to the main surface portion 7 of the semiconductor substrate 1 by the n-th step A5, and the n-th filling operation is completed, as shown in FIG. If the non-through hole 2 is filled with the conductive material 6, the process proceeds to step A8. If the filling operation is less than n times, the filling operation is repeated. An operation from filling a plurality of times to filling the non-through hole 2 with a conductive material may be referred to as a filling operation.

  The first working pressure and the second working pressure of each filling operation in the filling work are from the start of the filling operation until the conductive material 6 is filled in the non-through hole 2 by performing a predetermined number of filling operations. When the filling operation is performed, the pressure difference between the first working pressure and the second working pressure is adjusted to be smaller as the subsequent filling operation is started. For example, as shown in FIG. 4A, when the number of repetitions of the filling operation is n (n is an integer of 2 or more), the second filling operation and the nth filling operation which is the last filling operation. The pressure difference ΔPi between the second working pressure Pi [2] and the first working pressure Pi [1] in the i-th filling operation between and the filling operation after the i-th and before the n-th filling operation When compared with the pressure difference ΔPj between the second working pressure Pj [2] and the first working pressure Pj [1] in the j-th filling operation, which is the operation, ΔPj is adjusted to be smaller than ΔPi. Further, the second working pressure Ps [2] and the first working pressure Ps [1] in an arbitrary s-th filling operation between the second filling operation and the n-th filling operation which is the last filling operation. The pressure difference ΔPs is compared with the pressure difference ΔP (s−1) between the second working pressure P (s−1) [2] and the first working pressure P (s−1) [1] of the s−1th time. In this case, ΔPs is adjusted to be equal to or less than ΔP (s−1).

  Further, the volume V1 of the conductive material 6 supplied to the surface portion 8 of the semiconductor substrate 1 by the printing operation in step A5 in the first filling operation is the total volume of the conductive material supplied to the semiconductor substrate 1 throughout the filling operation. The volume is adjusted to be smaller than the volume Vm / n obtained by dividing Vm by the number of filling operations n. The supply amount of the conductive material supplied to the main surface portion 7 of the semiconductor substrate 1 is adjusted, for example, by the moving speed of the squeegee 5 that slides on the surface of the print mask 4. Since the conductive material 6 has viscosity, when the moving speed of the squeegee 5 is high, the volume of the conductive material that moves to the hole 10 of the printing mask 4 is reduced as compared with the case where the moving speed of the squeegee 5 is low. The volume of the conductive material 6 supplied to the surface portion of the semiconductor substrate 1 can be reduced. Further, when the moving speed of the squeegee 5 is low, the volume of the conductive material 6 supplied to the main surface portion 7 of the semiconductor substrate 1 is larger than when the moving speed of the squeegee 5 is high.

  In the present embodiment, the filling operation is repeated three times. For example, the first working pressure in each filling operation is adjusted to 2 kPa or less. Further, for example, the first working pressure of the second filling operation is adjusted to be larger than 2 kPa and smaller than 10 kPa. For example, the first working pressure of the last filling operation is adjusted to 7 kPa or more and less than 10 kPa. In the present embodiment, as shown in FIG. 4B, the first working pressure in each filling operation is adjusted to 0.5 kPa in the first filling operation, 5 kPa in the second filling operation, In the last filling operation, the pressure is adjusted to 7 kPa. The second working pressure adjusts the atmosphere in the chamber to atmospheric pressure. That is, in the present embodiment, in the second work pressure adjustment work in step A6 in the filling work, the first work pressure is released to the atmospheric pressure.

  In the present embodiment, the moving speed of the squeegee 5 in the printing operation in step A5 is set to 20 mm / sec and 30 mm / sec, for example. When the moving speed of the squeegee 5 is set to 30 mm / sec, the volume of the conductive material 6 filled in the non-through holes 2 is half the volume of the holes 10 of the printing mask 4. In the present embodiment, the moving speed of the squeegee 5 is set to 30 mm / sec in the first filling operation, and the conductive material 6 is supplied to the main surface portion 7 of the semiconductor substrate 1. Next, the conductive material 6 is filled into the non-through hole 2 as shown in FIG. 3B by the pressure difference inside and outside the non-through hole 2 at step A6. In the second filling operation, the moving speed of the squeegee 5 in step A5 is set to 20 mm / sec, and the conductive material having a volume larger than that of the conductive material 6 supplied in the first filling operation as shown in FIG. 6 is supplied to the main surface portion 7 of the semiconductor substrate 1. Next, the conductive material 6 is filled in the non-through hole 2 as shown in FIG. 3 (d) by the differential pressure inside and outside the non-through hole 2 in step A6. In the third filling operation, which is the last filling operation, the moving speed of the squeegee 5 in step A5 is set to 30 mm / sec, and the conductive material 6 having the same volume as the conductive material 6 supplied in the first filling operation is used as the semiconductor substrate. 1 to the main surface portion 7. Next, as shown in FIG. 3E, the conductive material 6 is filled into the non-through hole 2 by the differential pressure inside and outside the non-through hole 2 in step A6.

  In step A8, the non-through hole 2 is filled with the conductive material 6, and the filling operation of the conductive material 6 into the non-through hole 2 is completed. When the filling operation is completed and the conductive material 6 is cured, the process proceeds to Step A9.

  In step A9, a cap metal forming operation for forming a cap metal is performed. In step A9, the resist mask 11 formed on the main surface portion 7 of the semiconductor substrate 1 is peeled off, and a metal is attached to the exposed surface of the conductive material 6 on the opening 9 side to form a cap metal layer (not shown). The cap metal layer is formed by depositing a metal such as aluminum by sputtering, for example. Further, a resist is formed, and metal layers other than the necessary portions are removed by wet etching to form a cap metal layer. When the cap metal layer is formed, the process proceeds to Step A10.

  In step A <b> 10, a through hole forming operation for grinding the back surface portion 8 of the semiconductor substrate 1 and exposing the conductive material 6 from the back surface portion 8 of the semiconductor substrate 1 is performed. In step A10, the back surface portion 8 of the semiconductor substrate 1 is retracted to the main surface portion 7 side by, for example, mechanical grinding, and the conductive material 6 is exposed to the outside of the semiconductor substrate 1 from the back surface portion 8 side. In the present embodiment, since the depth D of the non-through hole 2 is 150 μm, the semiconductor substrate 1 is ground so as to have a thickness of 100 μm, for example. When the grinding is completed, the process proceeds to Step A11.

  In step A11, a back surface processing operation for processing the back surface portion 8 is performed. In Step A11, a back surface processing operation is performed to form a back surface insulating film on the back surface portion 8 of the semiconductor substrate 1 where the conductive material 6 is exposed from the main surface portion 7 and the back surface portion 8 side, and to form back surface wiring and back surface bumps. When step A11 is completed, a semiconductor device in which the through electrode is formed on the semiconductor substrate 1 can be formed.

  Table 1 shows that the inventor changed the first working pressure in the chamber in step A4 for the first filling operation in the method for forming the through electrode of the present embodiment, and did not penetrate after filling the conductive material 6 in step A6. This is a result of observing the presence or absence of the formation of voids (hereinafter sometimes referred to as “voids”) in the filled portions of the conductive material 6 in the holes 2. As described above, the moving speed of the squeegee 5 in step A5 was set to 30 mm / sec. In step A6, the atmosphere in the chamber was released to atmospheric pressure.

  As shown in Table 1, when the atmosphere in the chamber is higher than 2 kPa, voids may occur in the non-through holes 2. In the first filling operation of the present embodiment, since the atmosphere in the chamber in step A4 is adjusted to 0.5 kPa, formation of voids can be reliably prevented.

  Table 2 shows that the first working pressure in the chamber in Step A4 is changed in the non-through hole 2 in Step A6 by changing the first working pressure in the chamber in Step A4 for the second filling operation in the method for forming the through electrode of the present embodiment by the inventor. It is the result of observing the presence or absence of the formation of voids due to the formation of voids and the spread of the diluent of the conductive material 6 on the resist mask 11. As described above, the moving speed of the squeegee 5 in step A5 was set to 20 mm / sec, and in step A6, the atmosphere in the chamber was released to atmospheric pressure.

  As shown in Table 2, when the atmosphere in the chamber in step A4 is around 5 kPa, voids are not formed in the non-through holes 2 and bleeding of the reactive diluent is not formed in the resist mask. The non-through hole 2 can be filled with the conductive material 6. When it is 10 kPa or more, a void is formed in the non-through hole 2 when the conductive material 6 is filled, and when it is 2 kPa or less, a bleeding of the reactive diluent contained in the conductive material 6 is formed in the resist mask 11. In the second filling operation of the present embodiment, since it is 5 kPa, formation of voids can be surely prevented and bleeding can be prevented.

  Table 3 shows that the inventor changed the first working pressure in the chamber in step A4 for the third filling operation, which is the last filling operation in the method for forming the through electrode according to the present embodiment. This is a result of observing the formation of voids in the non-through holes 2 and the presence or absence of bleeding of the conductive material 6 on the resist mask 11. As described above, the moving speed of the squeegee 5 in step A5 was set to 30 mm / sec. In step A6, the atmosphere in the chamber was released to atmospheric pressure.

  As shown in Table 3, when the atmosphere in the chamber in step A4 is less than 10 kPa, voids are not formed in the non-through holes 2, and bleeding of the reactive diluent is formed in the resist mask 11. Absent. When the pressure of the atmosphere in the chamber is 10 kPa or more, voids are formed in the non-through holes 2 when the conductive material 6 is filled. When the pressure is 2 kPa or less, the resist mask has bleeding of the reactive diluent contained in the conductive material. It is formed. In the final filling operation of the present embodiment, the pressure in the chamber is 7 kPa, so that formation of voids can be surely prevented, and bleeding of the diluent into the resist mask 11 can be prevented.

  FIG. 5 is a diagram for explaining the difference in the filling state of the conductive material in the non-through holes due to the difference in the volume of the conductive material supplied to the surface portion of the semiconductor substrate 1 in the first filling operation. 5, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 5A, when the volume of the conductive material 6 that closes the opening 9 of the non-through hole 2 is large, the conductive material 6 is filled by the differential pressure generated inside and outside the non-through hole 2 in step A6. The speed at which the conductive material 6 enters the non-through hole 2 is reduced. Therefore, as shown in FIG. 5B, the conductive material 6 is not filled up to the bottom surface portion 13 of the non-through hole 2, and therefore the bottom surface portion 13 of the non-through hole 2 and the bottom surface portion of the non-through hole 2 of the conductive material 6. A void 14 is formed between the surface facing 13. Further, as shown in FIG. 5C, when the volume of the conductive material 6 that closes the opening 9 of the non-through hole 2 is small, the conductive material 6 is caused by the differential pressure generated inside and outside the non-through hole 2 in step A6. The rate at which the conductive material 6 enters the non-through hole 2 when filling is increased. Therefore, as shown in FIG. 5D, the conductive material 6 is filled up to the bottom surface portion 13 of the non-through hole 2, and the bottom surface portion 13 of the non-through hole 2 and the bottom surface portion 13 of the non-through hole 2 of the conductive material 6. It is possible to prevent the formation of the void 14 between the surface facing the surface.

  Table 4 shows that the inventor adjusts the first working pressure in step A4 to 2 kPa for the first filling operation of the present embodiment, changes the moving speed of the squeegee 5 in step A5, and in step A6. It is the result of having observed the presence or absence of the formation of the void in the non-through-hole 2 with which the electrically-conductive material 6 was filled when adjusting the 2nd working pressure of this to atmospheric pressure.

  When the volume of the conductive material 6 supplied so as to close the opening 9 of the non-through hole 2 is large in the first filling operation, the present inventor compares the conductive material 6 with the small volume of the conductive material 6. It has been found that the speed of entering the non-through hole 2 becomes small. When the speed at which the conductive material 6 enters decreases, the conductive material 6 becomes viscous, so that the atmosphere between the bottom surface portion 13 of the non-through hole 2 and the surface of the conductive material 6 that faces the bottom surface portion 13 of the non-through hole 2. The gas volume cannot be shrunk and voids 14 are formed. As shown in Table 4, when the speed of the squeegee 5 during the printing operation in step A5 is 30 mm / sec or more, the conductive material 6 enters the bottom surface portion 13 of the non-through hole 2, and the non-through hole The formation of voids between the bottom surface portion 13 of the conductive material 6 and the surface facing the bottom surface portion 13 of the non-through hole 2 of the conductive material 6 can be prevented. In the present embodiment, the first working pressure in step A4 in the first filling operation is adjusted to 0.5 kPa, the moving speed of the squeegee in step A5 is set to 30 mm / sec, and the first working pressure in step A6 is set. The working pressure is released to atmospheric pressure. Therefore, the conductive material 6 is filled without forming voids up to the bottom surface portion 13 of the non-through hole 2.

  According to the through electrode forming method of the present embodiment, the volume of the conductive material 6 that fills the non-through hole 2 in a single filling operation is smaller than the volume of the non-through hole 2. The conductive material 6 can be reliably filled up to the surface of the opening 9 side of the non-through hole 2 in the conductive material 6 filled in the non-through hole 2 up to the portion 13 or before the previous filling operation. Therefore, voids can be prevented from being formed in the non-through holes 2, and voids can be prevented from being formed in the through electrodes formed by curing the conductive material 6.

  Further, since the filling operation of the conductive material 6 is repeated a plurality of times, even if a void is formed in the non-through hole 2 in the previous filling operation, the filling operation after the previous operation is not performed. Due to the differential pressure inside and outside the through hole 2, the gap formed so far can be reduced or eliminated. Therefore, since the non-through holes 2 can be filled with the conductive material 6 with a uniform density, it is possible to stably form through electrodes that have no variation in conductivity.

  According to the through electrode forming method of the present embodiment, when viewed through the entire conductive material filling process, the pressure difference between the first working pressure and the second working pressure is reduced as the subsequent filling operation is performed. Is set. Therefore, compared with the case where a pressure difference equal to or greater than the pressure difference between the first working pressure and the second working pressure in the first filling operation is adjusted in each filling operation, The pressure adjustment time of the atmosphere can be shortened, and the work in the filling operation becomes easy.

  According to the through electrode forming method of the present embodiment, in the second pressure adjustment operation, it is only necessary to open the atmosphere in the chamber to atmospheric pressure. Therefore, in the second pressure adjustment operation, the pressure is adjusted. In comparison, the time required for the second working pressure adjustment work can be shortened.

  According to the through electrode forming method of the present embodiment, in the first filling operation in the conductive material filling step, the pressure inside the non-through hole 2 is 2 kPa or less, and the pressure outside the non-through hole 2 is atmospheric pressure. Therefore, the conductive material 6 can be reliably filled up to the bottom surface portion 13 of the non-through hole 2 by the differential pressure between the atmospheric pressure and the pressure in the non-through hole 2. Since the through electrode is formed by filling the conductive material 6 with a uniform density up to the bottom surface, it is possible to stably form the through electrode without variation in conductivity. When the pressure in the non-through hole 2 is larger than 2 kPa, a void is formed in the non-through hole 2 filled with the conductive material 6.

  In the final filling operation, the pressure in the non-through hole is 7 kPa or more and less than 10 kPa, and the pressure outside the non-through hole is atmospheric pressure, so when filling the non-through hole 2 with the conductive material 6, the semiconductor Spreading over the resist mask 11 formed on the main surface portion 7 of the substrate 1 can be prevented. When the pressure in the non-through hole 2 is smaller than 7 kPa, when the conductive material 6 is filled in the non-through hole 2, the conductive material 6 spreads over the resist mask 11 formed in the main surface portion 7 of the semiconductor substrate 1, Bleeding is formed. If it is 10 kPa or more, the void 14 is formed in the non-through hole 2.

  According to the present embodiment, in the first filling operation in which the volume of the non-through holes 2 not filled with the conductive material is the largest in the entire conductive material filling process, the supply amount of the conductive material 6 is made the smallest, The through hole 2 is filled with a conductive material 6. Therefore, since the conductive material 6 can be reliably filled up to the bottom surface portion 13 of the non-through hole 2, the non-through hole 2 can be filled with the conductive material 6 with a uniform density. Therefore, the through electrode having no variation in conductivity can be stably formed.

  According to the present embodiment, since the conductive material 6 is supplied using the hole plate printing method, the conductive material 6 can be supplied to the main surface portion 7 of the semiconductor substrate 1 at a low cost. Therefore, the cost for forming the through electrode on the semiconductor substrate can be reduced.

  According to the present embodiment, the non-through holes 2 are filled with a conductive material with a uniform density, the through electrodes are formed on the semiconductor substrate 1, and the semiconductor device formed by the semiconductor substrate 1 is manufactured. In addition, the yield of the semiconductor device can be improved.

  The semiconductor device provided with the through electrode by the through electrode forming method of the present embodiment is formed by the semiconductor substrate 1 having a thickness of 100 μm. Therefore, when this semiconductor device is stacked and a stacked semiconductor device is formed, the stacked semiconductor device is stacked. The type semiconductor device can be reduced in size. Accordingly, it is possible to reduce the size of an electronic device equipped with a stacked semiconductor device.

  As another embodiment of the present invention, for example, when the pressure difference between the first working pressure and the second working pressure of each filling operation in the conductive material filling process is viewed throughout the conductive material filling process, You may set so that it may become small as it becomes.

  Compared with the case where a pressure difference equal to or greater than the pressure difference between the first working pressure and the second working pressure in the first filling operation is adjusted in each filling operation, the first working pressure and Adjustment time with the second working pressure can be shortened, and work in the filling operation is facilitated.

  As still another embodiment of the present invention, the pressure difference between the first working pressure and the second working pressure in at least one filling operation among the filling operations repeated a plurality of times in the conductive material filling step is calculated as the previous filling. You may adjust so that it may become larger than the pressure difference of the 1st working pressure in operation, and the 2nd working pressure.

  In this way, by adjusting the pressure difference between the first working pressure and the second working pressure in the conductive material filling step, a void should be formed in the non-through hole 2 by the previous filling operation. However, since the formed void can be surely eliminated or reduced, the non-through holes 2 can be filled with the conductive material 6 with a uniform density, and the through electrodes without variations in conductivity can be stably formed. can do.

  As still another embodiment of the present invention, the supply amount of the conductive material to the main surface portion 7 of the semiconductor substrate 1 in each filling operation becomes smaller as it becomes the previous filling operation when viewed through the entire conductive material filling process. You may set as follows.

  By setting the supply amount of the conductive material in this manner, the main surface portion of the semiconductor substrate 1 is the first filling operation in which the volume in the non-through hole 2 not filled with the conductive material is the largest in the entire conductive material filling process. The supply amount of the conductive material 6 to 7 is made the smallest, and the non-through hole 2 is filled with the conductive material 6. Therefore, since the conductive material 6 can be reliably filled up to the bottom 13 of the non-through hole 2, the conductive material 6 can be filled into the non-through hole 2 with a uniform density. Therefore, the through electrode having no variation in conductivity can be stably formed.

  As still another embodiment of the present invention, a dispensing method can be used instead of the hole plate printing method.

It is a flowchart which shows the formation method of the penetration electrode which is one Embodiment of this invention. It is a figure which shows the outline | summary of the filling process in the formation method of the penetration electrode which is one Embodiment of this invention. It is a figure which shows the filling process in the formation method of the penetration electrode which is one Embodiment of this invention in detail. It is a graph which shows transition of the pressure of the atmosphere in the chamber of the filling process in the formation method of the penetration electrode which is one embodiment of the present invention. It is a figure for demonstrating the difference in the filling state of the electrically-conductive material in a non-through-hole by the difference in the volume of the electrically-conductive material supplied to the surface part of the semiconductor substrate by the first filling operation. It is sectional drawing of the semiconductor substrate in which the penetration electrode was formed. It is sectional drawing of the semiconductor substrate in which wiring and the penetration electrode were provided. It is a figure for demonstrating the method of forming a penetration electrode in a semiconductor substrate using the 1st conventional technique. It is a flowchart which shows filling operation to the non-through-hole of the electrically conductive material of the 2nd prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Non-through-hole 3 Insulating film 4 Print mask 5 Squeegee 6 Conductive material 7 Main surface part 8 Back surface part

Claims (8)

A non-through hole forming step for forming a non-through hole in the substrate that is open at the surface portion on one side in the thickness direction and is closed at the surface portion on the other side in the thickness direction;
An insulating film forming step of forming an insulating film on the inner wall of the substrate in the non-through hole;
A conductive material having a volume smaller than the volume of the non-through hole is supplied to the surface portion on one side in the thickness direction of the substrate to close the opening of the non-through hole, Filling the conductive material by repeating the filling operation of filling the non-through hole with the conductive material by making the pressure in the space higher than the pressure of the non-through hole and filling the non-through hole with the differential pressure inside and outside the non-through hole. Process,
A through hole forming step of retracting the other surface of the substrate until the conductive material is exposed to the outside.   2. The conductive material filling step, wherein the differential pressure inside and outside the non-through hole in each filling operation is set so as to become smaller as the subsequent filling operation is viewed through the whole conductive material filling step. The formation method of the penetration electrode of description.   The differential pressure inside and outside the non-through hole in at least one filling operation among the filling operations executed in the conductive material filling step is set to be larger than the differential pressure inside and outside the non-through hole in the previous filling operation. The method for forming a through electrode according to claim 1 or 2.   In the conductive material filling step, the conductive material is supplied to the surface portion on one side in the thickness direction of the substrate in an atmosphere adjusted to a pressure lower than the atmospheric pressure to close the opening of the non-through hole, The method for forming a through electrode according to claim 1, wherein the non-through hole is filled with a conductive material by returning the atmospheric pressure to atmospheric pressure.   In the first filling operation, a conductive material is supplied to the surface portion on one side in the thickness direction of the substrate in an atmosphere adjusted to a pressure of 2 kPa or less. In the last filling operation, the atmosphere is adjusted to a pressure of 7 kPa or more. The method for forming a through electrode according to claim 4, wherein a conductive material is supplied to the surface portion on one side in the thickness direction of the substrate.   In the conductive material filling process, the supply amount of the conductive material to the surface portion on one side in the thickness direction of the substrate in each filling operation is set so as to become smaller as it becomes the previous filling operation when viewed through the entire conductive material filling process. The method for forming a through electrode according to claim 1, wherein the through electrode is formed.   The formation of the through electrode according to any one of claims 1 to 6, wherein in the conductive material filling step, the conductive material is supplied to the surface portion on one side in the thickness direction of the substrate using hole plate printing. Method.   The manufacturing method of the semiconductor device using the formation method of the penetration electrode as described in any one of Claims 1-7.

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