JP5943369B2 - Thermally conductive laminated film member and manufacturing method thereof, heat dissipation component and heat dissipation device using the same - Google Patents

Description

  The present invention relates to a heat conductive laminated film member that can be suitably used in the electronics field and the automobile waste heat utilization field that require effective transfer of heat generated from electronic equipment and semiconductor devices, and a method for manufacturing the same, The present invention relates to a heat radiating component and a heat radiating device.

  Conventionally, a method of attaching a heat sink, a method of radiating heat to a substrate, and the like have been taken for cooling semiconductor devices. Examples of such applications include optical devices such as semiconductor laser diodes and light emitting diodes, and electronic devices such as MOS field effect transistors and heterojunction field effect transistors. Specifically, in a single laser chip, a method of radiating heat using a heat sink made of a material having high thermal conductivity such as Cu or Al is used. In semiconductor elements such as Si chips and these modules, a method of radiating heat from a heating element or the like to a substrate via a lead is widely used. Or, for heat dissipation and transfer of heat generated from semiconductor devices such as electronic equipment, electronic devices, and optical devices, heat exchange with liquid is performed to transfer heat to a fluid, or heat is transferred to a material with high thermal conductivity The correspondence is mentioned.

  However, evaporating and aggregating heat transfer modules such as heat pipes are limited in the direction, size, and configuration of the heat transport path, and are particularly limited in downsizing of equipment. In addition, the conventional method of transferring heat with a material having high thermal conductivity has a problem that heat is released during the heat transfer process, so that a sufficient amount of heat transport cannot be obtained, and heat is released during the heat transfer process. There was an adverse effect on the equipment due to diffusion, etc. Although there is a conventional technique described in the above-mentioned Patent Document 1, an anisotropic heat conductive material is obtained by suppressing the heat conductivity in the film thickness direction, rather than improving the heat conductivity in the film direction. Since it aims at obtaining, it has not led to an improvement in essential thermal conductivity.

JP 2006-229174 A

  In view of the above problems, the present inventor has proposed a heat conductive film that enables efficient heat dissipation and transfer of heat generated from a heating element in a space-saving manner (see Japanese Patent No. 4430112). This is formed by laminating a heat conductive layer containing graphite and a strain relaxation layer made of specific silicon or the like, thereby effectively solving the above-described problems.

  Therefore, the present inventor has further applied this technique to try to obtain a film member that has been subjected to processing applicable to various semiconductor devices, for example. However, it has been found that there is no suitable processing method for performing deep drilling or the like on the heat conductive laminated film, and it is difficult to obtain a structural member having a desired shape.

  There are mechanical processing methods such as sandblasting and drilling, but there is a limit to the miniaturization of the processing shape. In addition, it is difficult to realize the smoothness of the processed wall surface, and when the heat dissipating member or the like is disposed and used, sufficient adhesion cannot be obtained, and as a result, heat dissipation as expected can not be obtained. .

Accordingly, a first object of the present invention is to efficiently etch and process a laminated film including a heat conductive layer containing graphite and finely penetrate, for example, the heat conductive layer and a strain relaxation layer such as specific silicon. It is providing the manufacturing method of the heat conductive laminated film member which enables deep digging of a width.
A second object of the present invention is to enable efficient heat dissipation and transfer of heat generated from a heating element in a space-saving manner by using a heat conductive laminated film member having a fine processed portion manufactured by the above manufacturing method. The heat conductive film heat radiating component and the heat radiating device are provided.

The above problem has been solved by the following means.
(1) A method for producing a heat conductive laminated film member, wherein a heat conductive laminated film formed by laminating a heat conductive layer and a strain relaxation layer is processed by reactive ion etching,
Graphite is selected as the material constituting the heat conductive layer, and any of amorphous Si, amorphous Ge, amorphous SiGe, amorphous SiO ₂ , amorphous SiO x, amorphous TiO ₂ , and combinations thereof is used as the material constituting the strain relaxation layer. Select
Using an oxygen-containing gas that etches the thermal conductive layer, a sulfur-fluorine compound-containing gas that etches the strain relaxation layer, and a fluorocarbon compound-containing gas that protects the etched surface, the at least three kinds of gases are switched. While applying etching in the order of the sulfur-fluorine compound-containing gas, the oxygen-containing gas, and the fluorocarbon compound-containing gas, a protective film is formed on a processing wall during the etching using the fluorocarbon compound-containing gas, and the protection A film is left after the etching using the sulfur-fluorine compound-containing gas and the etching using the oxygen-containing gas, and the film is processed to penetrate the heat-conducting laminated film, and the method for producing a heat-conducting laminated film member .
(2) The method for producing a heat-conducting laminated film member according to (1), wherein the heat-conducting layer and the strain relaxation layer are alternately laminated one by one or plural layers.
(3) Manufacturing of the heat conductive laminated film member according to any one of (1) and (2), wherein the heat conductive layer and the strain relaxation layer each have a thickness of 1 nm to 20 nm. Method.
(4) When processing by the reactive ion etching is performed in a process chamber, supply is performed when any one of oxygen-containing gas, sulfur-fluorine compound-containing gas, and fluorocarbon compound gas is supplied in combination. The method for producing a thermally conductive laminated film member according to any one of (1) to (3), wherein the amount of gas to be supplied is 100 sccm or less.
(5) Any one of (1) to (4), wherein O ₂ is used as the oxygen-containing gas, SF ₆ is used as the sulfur-fluorine compound-containing gas, and C ₄ F ₈ is used as the fluorocarbon compound. The manufacturing method of the heat conductive laminated film member of Claim 1.
(6) A heat conductive laminated film member having a processed structure part formed by laminating a heat conductive layer and a strain relaxation layer and penetrating the heat conductive layer and the strain relaxation layer,
The processing unit wall surface of the processing structure has irregularities,
The thermally conductive layer is made of graphite, and the strain relaxation layer is made of amorphous Si, amorphous Ge, amorphous SiGe, amorphous SiO ₂ , amorphous SiO x, amorphous TiO ₂ , or a combination thereof,
The processed structure has a hole shape having an opening shape other than a circle, a groove shape, or a patterned notch shape,
The processing structure of the groove along the direction toward the heat dissipating member connected to the heat conductive laminated film member on the heat conductive laminated film member excluding the position of the heat conductive laminated film member corresponding to the place where the element is disposed The heat conductive laminated film member characterized by the above-mentioned.
(7) The heat conductive laminated film member according to (6), which has a taper in the vicinity of the outer surface of the processed structure portion.
(8) The heat conductive laminated film member according to (6) or (7), wherein the heat conductive layer and the strain relaxation layer each have a thickness of 1 nm to 20 nm.
(9) The number of laminations of the processed structure portion that penetrates the heat conductive layer and the strain relaxation layer is 2 or more and 4000 or less, (6) to (8), Thermally conductive laminated film member.
(10) The heat conduction according to any one of (6) to (9), wherein a work width of a work structure portion penetrating the heat conduction layer and the strain relaxation layer is 100 nm to 300 μm. Laminated film member.
(11) A heat dissipation component combining the heat conductive laminated film member according to any one of (6) to (10) and a heat radiating member, A heat dissipating part, wherein a part of the heat dissipating member is arranged.
(12) A heat radiating device comprising the heat radiating component and the element according to (11).
(13) The heat conductive laminated film member according to any one of (6) to (10) bonded to a silicon substrate, a semiconductor element mounted on the silicon substrate, and heat generated by the semiconductor element An LSI comprising a heat spreader that receives through a laminated film member and releases the heat to the outside,
A non-circular cross-sectional via hole penetrating the silicon substrate and the heat conductive laminated film is formed, and a heat conductive via post is embedded in the via hole, and the heat conductive laminated film is disposed in a plane direction through the via post. An LSI characterized by having a structure for transferring transmitted heat to the heat spreader.
(14) A large number of joined bodies of the silicon substrate and the thermally conductive laminated film are laminated, and via posts are provided in continuous via holes passing through the laminated bodies, and the via posts transfer heat to the heat spreader. The LSI according to (13), which is connected in such a manner.

  According to the manufacturing method of the present invention, a laminated film including a heat conductive layer containing graphite is efficiently etched and processed, for example, a fine width that penetrates the heat conductive layer and a strain relaxation layer such as specific silicon. Enables deep drilling. In addition, the heat conductive laminated film member of the present invention has a processed part such as a fine through hole processed into a desired shape, and by using this, an efficient heat dissipation and transfer of heat generated from the heating element is performed. It can be set as the heat conductive film heat radiating component and heat radiating device which were enabled by space saving.

It is sectional drawing which shows typically the structure of the heat conductive laminated film (before an etching) used as embodiment of this invention. It is explanatory drawing for demonstrating the process procedure of a sputtering film forming method. It is sectional drawing of the heat conductive laminated film in the middle of a process which shows typically a part of etching process in one Embodiment of this invention. It is sectional drawing of the heat conductive laminated film in the middle of a process which shows typically a part of etching process in the said embodiment of this invention. It is sectional drawing of the heat conductive laminated film in the middle of a process which shows typically a part of etching process in the said embodiment of this invention. It is sectional drawing of the heat conductive laminated film in the middle of a process which shows typically a part of etching process in another embodiment of this invention. It is the figure which showed typically the heat generating element mounting heat radiating device using the heat conductive laminated film as a reference example, (a) is a top view, (b) is a BB arrow directional cross-sectional view, (C) is CC sectional view taken on the line. FIG. 3 is a cross-sectional contour diagram schematically showing the shape of the opening or cross section of the via in the present invention. It is the figure which showed typically the heat generating element mounting heat radiating device using the heat conductive laminated film as one Embodiment of this invention, (a) is a top view, (b) is a BB arrow directional cross section. It is a figure and (c) is CC sectional view taken on the line. It is the figure which showed typically the heat generating element mounting heat radiating device which concerns on another embodiment of this invention, the upper figure is a sectional side view, and the lower figure is a top view. It is the figure which showed typically the modification of the etching process which concerns on embodiment of this invention. It is the figure which showed typically the modification of the etching process which concerns on embodiment of this invention. It is sectional drawing which showed typically the example which applied the heat generating element mounting thermal radiation device structure which concerns on embodiment of this invention to single layer LSI. It is sectional drawing which showed typically the example which applied the heat generating element mounting thermal radiation device structure which concerns on embodiment of this invention to laminated LSI. It is the element structure figure used for the simulation which evaluates the thermal radiation performance of the thermal radiation device concerning a 2nd embodiment of the present invention. It is a FEM model figure used for the simulation which evaluates the thermal radiation performance of the thermal radiation device which concerns on 2nd Embodiment of this invention.

<First Embodiment>
In this embodiment, the heat conductive laminated film formed by laminating a specific heat conductive layer and a specific strain relaxation layer is processed by a novel reactive ion etching to produce a heat conductive laminated film member. Details of the configuration will be described below.

(Thermal conductive laminated film)
FIG. 1 is a sectional view showing a heat conductive film according to the present embodiment. The heat conductive film 1 is a material containing C (carbon), specifically made of graphite, and conducts heat in the in-film direction (plane direction) X. And as a laminated film, the heat conductive layer 1 which consists of a 1st structural material, and the distortion | strain relaxation layer 2 which consists of the 2nd structural material which relieve | moderate the distortion | strain are laminated | stacked and comprised. Reference numeral 4 denotes a silicon (Si) substrate. As a result, a heat conductive film having a very thin film and a very high heat conductivity in the in-film direction can be obtained.

-Thermally conductive layer As a graphite applied as a constituent material of a thermally conductive layer, what can obtain the high thermal conductivity of 1500-2000 W / mK by HOPG (highly oriented graphite) which is excellent in crystallinity is preferable. Moreover, what has the further high heat conductive characteristic of 3000 W / mK or more by nano carbon may be used. In this heat conductive film, graphite is selected as the first constituent material of the heat conductive layer 1, but it is not completely crystallized as a hexagonal plate-like crystal usually called graphite. Also good. Moreover, components other than graphite may be contained in the heat conductive layer as long as the effects of the present invention are not impaired.
The thickness d of the heat conductive layer is preferably in the range of 1 nm to 20 nm, and more preferably 3 nm to 15 nm. When the heat conduction layer is too thin, graphite nuclei are formed immediately above the Si layer, and the next Si layer is formed before the distortion of the graphite layer can be fully relaxed, so the crystallinity of the graphite layer does not improve. Sometimes. On the other hand, if the film thickness of the heat conduction layer is too large, that is, if the graphite layer is too thick, disturbance will occur again when graphite is deposited on the highly oriented graphite layer. There is. For this reason, it is considered that the crystallinity of the graphite layer is lowered again.

In-strain relaxation layer present embodiment, as the material constituting the strain relaxation layer, selected amorphous Si, amorphous Ge, amorphous SiGe, amorphous SiO _2, amorphous SiOx, amorphous TiO _2, and any of these combinations. Among these, it is particularly preferable to use amorphous Si.

  The thickness t of the strain relaxation layer is preferably in the range of 1 nm to 20 nm, and more preferably in the range of 3 nm to 15 nm. When this strain relaxation layer is too thin, the unevenness of the lower heat conduction layer is not covered with the strain relaxation layer, and becomes the next heat conduction layer before flattening. On the other hand, when the strain relaxation layer is too thick, the crystallinity of the heat conductive layer is deteriorated as described above, and the strain relaxation effect is less likely to act. Further, it is preferable to select an amorphous material as the constituent material of the strain relaxation layer.

-Laminated structure In this embodiment, the crystallinity of graphite improves and the in-film thermal conductivity of the heat conducting layer improves by laminating the heat conducting layer made of graphite in combination with the strain relaxation layer. . As a result, a heat conductive film having a very thin film and a very high heat conductivity in the in-film direction can be obtained.

  In the present embodiment, the heat conductive layer and the strain relaxation layer may be alternately and repeatedly stacked a plurality of times, and the heat conductive layer may be sandwiched between the strain relaxation layers. According to this aspect, the heat conductivity in the in-film direction (in-film heat conductivity) can be improved by setting the number of laminated layers of the heat conductive layer and the strain relaxation layer as appropriate, and sufficient in the in-plane direction. A large amount of heat transport. The number of stacked layers is not particularly limited, but is limited by the trade-off relationship between the cooling effect and the film formation cost. It is preferably 2 or more and 4000 or less, more preferably 100 or more and 3000 or less, and particularly preferably 500 or more and 2000 or less.

  In order to improve the crystallinity of the thinned graphite, it is preferable to sandwich the strain relaxation layer between the heat conduction layers so as to effectively relax the strain of the graphite crystal. At this time, if the proportion of the heat conduction layer (graphite) is too small, not only will the heat transfer material be reduced, but distortion will not be alleviated and no improvement in crystallinity can be expected. The conductivity is difficult to improve. On the other hand, if the proportion of the heat conductive layer (graphite) is too large, the crystallinity of the graphite deteriorates, and the heat conductivity in the in-film direction of the heat conductive layer is difficult to improve.

  In consideration of such points, in this embodiment, it is preferable that the relationship between the film thickness d of the heat conduction layer and the film thickness t of the strain relaxation layer satisfy the following expression (1). ) Is more preferable.

0.4 ≦ d / (d + t) ≦ 0.8 (1)
0.5 ≦ d / (d + t) ≦ 0.7 (2)

(Film forming method)
In the present invention, the method for forming the laminated film is not particularly limited, and examples thereof include known methods such as ion beam sputtering, ion cluster beam, and MBE. The sputtering method will be described in detail. A method of alternately stacking two types of films while switching two types of targets is mentioned. FIG. 2 schematically shows this situation. The film forming procedure is as follows.
1: A sample to be coated and a film material (target) are placed close to each other.
2: The whole is evacuated and a voltage is applied between the sample and the target.
3: Electrons and ions move at high speed, and the ions collide with the target. Electrons and on that move at high speed collide with gas molecules, repel the electrons of the molecules, and become ions.
4: Ions colliding with the target repel target particles (sputtering phenomenon).
5: The repelled raw material particles collide and adhere to the sample to form a film.

(etching)
3-6 is sectional drawing of the heat conductive laminated film in the middle of a process which shows typically a part of etching process in preferable embodiment of this invention. In the present embodiment, known reactive ion etching can be applied to the etching of the strain relaxation layer. For example, it is preferable to use the Bosch method. Even when SiGe or Ge is used in place of the specific Si constituting the strain relaxation layer, it can be etched with a sulfur-fluorine compound, preferably SF ₆ , similarly to the Si film.

On the other hand, the graphite constituting the heat conductive layer is difficult to etch by the Bosch method, and is etched with oxygen (0 ₂ ) gas. In the present invention, this graphite (carbon) -containing layer is characterized by etching with oxygen gas, which is important. By performing etching by appropriately combining these two kinds of gases, it is possible to perform deep processing so as to penetrate the heat conduction layer made of graphite and the strain relaxation layer made of specific silicon or the like. In the present specification, “penetrating” or “penetrating” each layer refers to removing a part of the planar area of each layer and continuing the space in the thickness direction, in addition to penetrating in a cylindrical shape, and any arbitrary The shape may be penetrated, and groove-shaped processing and notch processing of the end portion are also included in the meaning of the term of processing to penetrate or penetrate.

In the present invention, a gas for forming a protective layer is further applied to the etching process. As a result, desired anisotropic etching is achieved, and deep etching that penetrates the laminated film in a desired opening shape or cross-sectional shape becomes possible. A fluorocarbon compound is preferably applied as the protective gas, preferably C ₄ F ₆ (such as hexafluoro-1,3-butadiene) or C ₄ F ₈ (such as perfluorocyclobutane), and particularly preferably C ₄ F ₈ . As the formation of micropores in the Bosch method, Chienliu Chang et al. Micromech. Microeng, 15 (2005) 580-585, etc. can be referred to, and the equipment and process conditions applied there can be referred to.

3 to 6 will be described in more detail. In step <1> of FIG. 3, first, the strain relaxation layer 2 made of specific silicon or the like is etched with SF ₆ gas. An etching mask 5 is attached to portions other than the portion to be etched. As an etching mask, a general etching mask of this type can be applied. Next, the etching gas is switched to oxygen gas, and the heat conductive film made of graphite is etched (step <2> in FIG. 3). Thereafter, the processing surface (processing wall surface Km, processing bottom surface kn) facing the processing portion K is protected by the protective gas (C ₄ F ₈ ) to form the protective film 6. In the figure, the thickness of the protective film 6 is drawn slightly exaggerated, but it is a very thin film or a modified surface state (step <3> in FIG. 4). Further, although the processed wall Km is depicted as having wavy irregularities, it is convenient for understanding, and in the present invention, it is one of the advantages that a wall without such irregularities is achieved.

Further, when etching with SF ₆ gas is performed, the shape of the processed wall km protected by the protective film is maintained as it is as in step <4> of FIG. 4, and only the processed bottom kn is etched. As a result, the machining width w is kept constant and deep machining can be performed with extremely high accuracy, and fine holes or grooves whose walls are straight in the longitudinal section can be formed. Next, the etching gas is switched to oxygen (O ₂ ) gas, and the heat conductive layer made of graphite is etched (step <5> in FIG. 5). By repeating these series of steps, a processed portion (fine hole or groove) K having a depth is obtained (step <6> in FIG. 5).

The order in which etching and protective film formation are performed with each gas is preferably SF ₆ => O ₂ => C ₄ F ₈ . In the etching process using SF6, first, the protective film on the hole bottom Kn is lost due to the etching anisotropy of ICP-RIE, and the protective film remains on the side wall Km (see <4> in FIG. 4). The exposed Si is isotropically etched by chemical bonding. Then, since the _{O 2} plasma isotropically etched even protective film due to heat conduction layer also _C 4 _{F 8} in the multilayer film, in <5> in FIG. 5, the film 6 by _C 4 _{F 8} by _{O 2} is , Isotropically etched and becomes considerably thinner or completely absent. At this time, if the protective film of C ₄ F _{8 is} completely lost and the heat conduction layer or the strain relaxation layer on the processed portion wall surface Km is etched, the verticality of the processed wall surface cannot be obtained. Therefore, in order to obtain the vertical workability of the processed wall surface, it is desirable that the protective film of C4F8 remains on the processed portion wall surface Km after the etching of SF ₆ and O ₂ . In other words, when it is desired to process the processed portion wall surface Km in a direction other than vertical, it can be realized by changing the thickness of the protective film by C4F8. However, the present invention is not limited to this description.

  FIG. 6 shows an application form of the etching process, in which an etching mask is disposed leaving the end of the laminated film, and etching with the predetermined gas is performed at the end. As a result, the notched portion K can be formed at the end of the laminated film.

In the production method of the present invention, it is preferable to use an appropriate combination of the two types of etching gas and the protective gas. The setting conditions and the like in the process chamber may be appropriately selected depending on the processing content, but the following settings are preferable in order to perform processing that is particularly fine and deep.
_<SF 6>
Gas supply amount: 80-100 sccm
Bias voltage: 15
RF power: 500
_<C 4 _F 8>
Gas supply amount: 40-60 sccm
Bias voltage: 0
RF power: 500
<O ₂ >
Gas supply amount: 30-50 sccm
Bias voltage: 20
RF power: 800

  By appropriately setting the above conditions, the laminated film can be etched into a desired shape. This is preferable because, for example, deep etching with a predetermined width and depth is possible. The processed form may be a hole shape, a groove shape, or a notch shape at the end. When defining as a dimension, if it is a hole shape or a groove shape, it can specify with the width | variety of a predetermined | prescribed cross section like what was shown in FIG. Strictly speaking, in the case of a hole shape, the hole area of the cross section is obtained, and the processing width w can be defined as the equivalent circle diameter. In the case of a groove shape, a longitudinal section where the groove width is the narrowest can be set and defined as the groove width w at that time. According to the present invention, an extremely fine etching process is also possible. For example, when performing a fine deepening, the process width w can be set to 100 nm to 300 μm. Furthermore, when meeting the need for miniaturization to a level that is difficult with mechanical processing methods, the processing width can be set to 100 nm to 1 μm, which is preferable.

(Performance evaluation of thermal conductive film)
Next, specific examples of the thermally conductive laminated film according to the first embodiment will be described based on Table 1 below.

  The manufacturing method of the heat conductive laminated film 1 of Examples 1-1 to 1-6 is as follows. On the single crystal Si (111) substrate 4, a multilayer film of the heat conductive layer 1 and the strain relaxation layer 2 was formed by ion beam sputtering. First, after the strain relaxation layer 2 made of amorphous Si (second constituent material) is formed on the Si substrate 4, the heat conduction layer 1 made of graphite C (first constituent material) and the strain relaxation layer made of amorphous Si. 2 were alternately formed, and finally, the strain relaxation layer 2 was formed as the uppermost layer.

The thermal conductivity characteristics of Examples 1-1 to 1-6 produced in this manner were measured. The heat conduction characteristics in the film thickness direction were measured by a thermoreflectance method. After depositing Mo on the sample surface, heating was performed by irradiating the center of the sample with a pulse laser. The spot diameter of the heating laser is 3 or 7 μm. In the thermoreflectance method, the heating laser and the detection laser were irradiated to the same place, the phase lag in the film thickness direction of the temperature wave was measured, and the film thickness direction thermal conductivity was obtained. On the other hand, the heat conduction characteristics in the in-film direction were measured by separating the heating laser and the detection laser by a distance r by the thermoreflectance method. Table 1 shows the in-film thermal conductivity and the film thickness direction thermal conductivity. The details of the results can be further referred to Japanese Patent No. 4430112.
The heat conductive laminated film and the Si substrate shown in Example 1-2 were etched. 100 nm of Al was used for the etching mask. For etching Si, SF ₆ gas was introduced into the process chamber at 85 sccm, and etching was performed with a power of 500 W. For the etching of C, O ₂ gas was introduced into the process chamber at 40 sccm and etching was performed with a power of 800 W. To form the protective film, C ₄ F ₈ gas was introduced into the process chamber at 50 sccm, and deposition was performed with a power of 500 W. The dimensions and the like of the heat conductive laminated film thus produced are shown below.

Second Embodiment
(Configuration example of heat dissipation device)
The second embodiment of the present invention relates to a device in which a heat conductive laminated film having a processed portion is produced as described above for a device having a heat generating portion. FIG. 7 is a plan view and cross-sectional views schematically showing the heat dissipation device of the present embodiment. According to this embodiment, the heat generated by a heating element such as a semiconductor device can be effectively transferred by the heat conductive film. Therefore, it is possible to realize a heat conductive film that enables efficient heat dissipation and transfer of heat generated by the heating element in a space-saving manner.

  The heat dissipation device 100 shown in FIG. 7 has a heat conductive laminated film 11 in which the heat conductive layer 1 and the strain relaxation layer 2 described in the first embodiment are laminated, and the laminated film has a cylindrical shape. A plurality of processed portions (via holes) K are formed (FIG. 7 is a reference example and shows a cylindrical via hole in an opening or a cross section). As described above, the processed portion (via hole) K is formed by using a reactive ion etching method in which two kinds of gases are combined (see the first embodiment). And this heat conductive laminated film 11 is arrange | positioned so that the main body board | substrate 14 may be coat | covered. The main body substrate 14 is also provided with a cylindrical processed portion Ka to form a cylindrical pore continuous with the processed portion K of the heat conductive laminated film 11 in the thickness direction of the device. The main body substrate 14 corresponds to the silicon substrate 4 of the first embodiment and can be used without particular limitation as long as it is a substrate material applied to this type of product.

  The main body substrate 14 incorporates an element 13. This element 13 is exothermic and includes, for example, a transistor and a semiconductor laser diode. Further, the processed portions K and Ka form a continuous hole, and the heat radiating member 12 is attached thereto. The heat radiating member includes a first member 12a, a second member 12b, and a third member 12c, and the second member (via) 12b passes through the pore as described above and spreads in a planar shape on both upper and lower surfaces. It is continuous with the (heat spreader) 12a and the third member (heat spreader) 12c. In addition, when the shape of a process part is a notch shape, you may make it arrange | position the 2nd member of a thermal radiation member so that it may fit. According to the first embodiment, the thermally conductive laminated film is processed with high dimensional accuracy, and specifically, a highly smooth shape is realized on the wall surface. Therefore, similarly, it is in close contact with the wall surface of the second member 12b of the heat dissipating member such as Cu via with almost no gap.

  The heat dissipating members (heat spreaders) 12a and 12c are preferably made of a material excellent in heat dissipation, and examples thereof include metal members such as copper / copper alloys and aluminum / aluminum alloys. Among these, it is preferable that the heat dissipation via formed of a copper material and a copper / copper alloy that can be easily joined are preferable.

  Although the thickness and size of each member are not particularly limited, typical dimensions of the element 13 include, for example, a transistor having a thickness of 1 μm to 10 μm and a vertical and horizontal length of 1 μm to 100 μm. is there. In that case, the thickness of the heat conductive laminated film 11 is practically about 1 μm to 10 μm, and the total thickness of the device is practically 10 μm to 300 μm. In such a case, the actual device dimensions are practically 100 μm to 10,000 μm in length and width.

  The advantage of this embodiment is that the heat radiation plate is not simply placed on the upper surface of the heat conductive laminated film 11, but the second member (via) 12 a of the heat radiation member vertically penetrated through the processed portion (via hole) K is provided. That is, it is in contact with the heat conductive layers 1, 1, 1. As a result, heat from the element propagating in the device is effectively transported in the surface direction by the heat conducting layers 1, 1, 1 of the heat conducting laminated film, and the heat is inadvertently released in the thickness direction. Therefore, heat can be effectively transferred to the entire heat radiation member 12 through the second member 12b. And the 1st member 12a and the 3rd member 12c of the heat radiating member 12 are spread in the shape of a plane, and are opened outside, and can realize extremely high heat dissipation. The difference in performance compared to the case where there is no processed portion (via hole) K and no heat dissipation via is shown is as follows.

  Further, in the present invention, it is important that the shape of the opening and the cross section of the via hole and the via post embedded in the via hole (sometimes simply referred to as a cross sectional shape) are other than circular. A preferred embodiment of the present invention is listed in FIG. (A) is a cross-shaped cross-section, (b) is a gear-shaped cross-sectional shape, (c) is a hexagonal cross-sectional shape, and (d) is a star-shaped cross-sectional shape. Such a cross-sectional shape other than a circle is difficult to realize by a mechanical processing method. As described above, in the present invention, by making the cross-sectional shape other than circular, it is possible to increase the contact area between the heat conductive laminated film and the via and reduce the thermal resistance between the two, and more excellent in heat dissipation. There is an advantage of realizing the device. For example, the heat flow in the device shown in FIG. 11 is as follows: heating element → Si substrate → multilayer film → multilayer film / radiation via contact interface → radiation via → connection paste → heat spreader. It can be evaluated that the thermal resistance is connected in series. Therefore, even when a high thermal conductive multilayer film having excellent thermal conductivity is used, if the thermal resistance is increased at the interface between the multilayer film and the heat dissipation via, the overall heat dissipation performance is lowered, and the characteristics of the high thermal conductivity multilayer film are not utilized. In other words, according to the present invention, by making the cross section of the via non-circular, it is possible to more effectively draw out the good thermal conductivity of the heat conductive laminated film, and the performance of the heat dissipation member or the entire device The heat dissipation can be increased synergistically.

(Performance evaluation of heat dissipation device)
Next, an example in which performance evaluation of the heat dissipation device according to the second embodiment is performed by simulation will be described based on Table 2 below.

* The laminated film prepared in Example 1-1 was formed on a device having a heat generating portion. The total thickness of the laminated film was 10 μm.

The conditions of this simulation are as follows. The analysis model used for the FEM was calculated using a prismatic model with a triangular cross section shown in FIGS.
Thermal conductivity of high thermal conductive multilayer film: 800 W / m / K (in-film direction), 1 W / m / K (film thickness direction)
Thermal conductivity of heat dissipation vias and heat spreaders (copper): 360 W / m / K
Thermal conductivity of bonding paste: 262W / m / K
Thermal conductivity of substrate (silicon): 148W / m / K
Interfacial thermal conductance between heat spreader and atmosphere: 2.5kW / m ² / K
Interfacial thermal conductance with other atmospheric surfaces: 10 W / m ² / K
Interfacial thermal conductance between heat dissipation via and bonding paste: 500kW / m ² / K
Interfacial thermal conductance between high thermal conductive multilayer film and bonding paste: 240kW / m ² / K
Interfacial thermal conductance between high thermal conductive multilayer film and heat dissipation via: 930kW / m ² / K
Environmental temperature: 23 ℃
Substrate (silicon) thickness: 425μm
Calorific value: 0.3W

  In the above evaluation, a temperature drop of several to several tens of points was confirmed with respect to the comparative example by the heat dissipation device according to the example of the present invention. This can be estimated as a temperature several to tens of degrees lower than that when the maximum temperature of the device of the comparative example is about 60 ° C. Further, in the above simulation, the heat dissipation via diameter Φ is set to a large value of 150 to 300 μm for convenience of calculation. However, according to the reactive ion etching described in the first embodiment, the via hole having a diameter Φ of less than 1 μm is used. Formation is also possible. As described above, when it is assumed that a large number of fine heat-dissipation vias having a thickness of less than 1 μm are provided on a substrate having a thickness of 30 to 50 μm, the above difference becomes more remarkable. Although it depends on the form of the heat spreader (heat radiating member), roughly speaking, it is estimated that the maximum temperature of the device of the comparative example is about 100 ° C, and the temperature can be lowered in the range of tens of degrees Celsius. Is done.

(Application etc.)
The device structure of this embodiment has little heat release and diffusion in the heat transfer process, and can obtain a sufficient amount of heat transport in the in-plane direction. This has the advantage of having a small impact. And it can use effectively for the heat dissipation of the electronic device and semiconductor device which are used in the electronics field | area where it is required to move the heat | fever which generate | occur | produces with a heat generating body effectively, a vehicle waste heat utilization field | area, etc. In addition, it can be used for cooling devices for portable devices that require space saving.

  As the semiconductor device of the present embodiment, for example, a plurality of semiconductor laser diodes arranged side by side, a condensing lens that collects light emitted from the plurality of semiconductor laser diodes, a cooling unit, and a plurality of semiconductor laser diodes And a plurality of the heat conductive films arranged so as to sandwich each of the laser diode modules. According to this module, heat from the plurality of semiconductor laser diodes can be transferred by the plurality of heat conductive films and escaped to the cooling means side. In addition, since heat from the active layers of a plurality of semiconductor laser diodes can be preferentially transferred to the side surface by a plurality of heat conductive films arranged so as to sandwich each semiconductor laser diode, the total heat radiation amount increases, The semiconductor device temperature can be reduced. Furthermore, the heat from the active layers of a plurality of semiconductor laser diodes that are multilayered can be effectively discharged.

  FIG. 9 shows another modification in which the heat conductive laminated film is modified. Specifically, the heat conductive laminated film is arranged only at a position corresponding to the place where the element 13 is arranged, and a groove L is formed along the direction from the element toward the heat radiating member in the other part. Formed. As a result, it is possible to efficiently perform heat radiation cooling without being affected by the adjacent element 13.

  FIG. 10 shows a taper provided in a via hole formed in a multilayer film. Thereby, especially in this embodiment, the film thickness of each layer is several to several tens of nanometers, and effects such as a large increase in the heat exchange area can be expected including effects due to the taper and the unevenness. Here, in FIG. 4 <4> or FIG. 5 <5> shown above, by controlling the etching amount of the Si film or C film, as shown in FIGS. What controlled the amount of taper etc. can be applied. In FIGS. 11-1 and 1-2, (a) is the same as that shown in FIGS. 4 and 5, and the vertical etching side wall is obtained by adjusting the etching amount optimally. (B) is the one in which only one of the heat conduction layer and the strain relaxation layer is subjected to side etching from the processed part wall surface Km after the vertical cross section of (a) is formed, and the processed part wall surface is processed into an uneven shape. Etching is performed by adjusting one or both of the conductive layer and strain relaxation layer to an insufficient etching amount), and (d) adjusts one or both of the heat conduction layer and strain relaxation layer to an excessive etching amount. Then, examples of those processed by etching and processed into a reverse taper are shown.

12 and 13 are examples in which the device structure according to the second embodiment is applied to a more specific electronic device. FIG. 12 shows a single-layer LSI, and FIG. 13 shows a stacked LSI. In the example of FIG. 12, a processor core is applied as the element 13, and this is mounted by the board | substrate 14a and the board | substrate 14b. The heat conductive laminated film 11 according to the above embodiment is disposed on the substrate 14a, and a heat spreader as a first member 12a of the heat radiating member is disposed on the opposite side of the substrate so as to sandwich the film. In the present embodiment, the via hole K is provided in the heat conductive laminated film 11, and this is the via hole Ka of the substrates 14a and 14b.
To be continuous. In this via hole, a Cu heat dissipation via (second member) is formed to pass through. Thereby, the heat which propagates transfers a heat | fever to the 1st member (heat spreader) 12a via this Cu via | veer (2nd member).

  FIG. 13 shows the structure of the stacked LSI, and solder balls 19 are attached to the bottom and can be mounted on a circuit board. The heat generating element (processor core) 13 is embedded in the Si chip 13A, and the Si chip is laminated in a plurality of layers. Each Si chip 13A is provided with the heat conductive laminated film 11 according to the above embodiment on the top thereof. Here, a via hole is provided, and the Si chip 13 and the heat conductive laminated film 11 of each layer continue through the Si chip 13 through the via hole. Cu vias (second member) are introduced into the via holes, and a heat transfer structure is formed so as to connect a plurality of Si chips. Using this heat dissipation via as the second member 12b, it is continuous with the first member (heat spreader) 12a of the heat dissipation member mounted on the uppermost part of the device, and the internal heat can be efficiently released to the outside. Note that the entire laminated LSI is sealed with a sealing resin 15.

  Also in the single-layer LSI and the multilayer LSI, the excellent advantages of the heat conductive multilayer film of the present invention are effectively utilized. That is, heat generated from the element is received by the heat conductive laminated film and is preferentially transferred in the plane direction while suppressing the shift in the thickness direction. The transferred heat is very efficiently transferred to the second member of the heat radiating member that is continuous with each heat conduction layer, and transferred to the first external member (heat spreader) 12a. Through such a selectively transferring heat conduction path, it is possible to dissipate and cool the single-layer LSI or the stacked LSI very effectively without inadvertently storing heat inside.

DESCRIPTION OF SYMBOLS 1 Thermal conductive layer 2 Strain relaxation layer 4 Silicon substrate 5 Etching mask 6 Protective film 11 Thermal conductive laminated film 12 Heat radiating member 12a 1st member 12b 2nd member 12c 3rd member 13 Element 13A Si chip 14 with built-in element Main body substrate 15 Sealing resin 100, 200, 300, 400, 500, 600 Heat dissipation device K Processing part (via hole)
Km Machined part wall surface Kn Processed part bottom face L Groove

Claims (14)

A method for producing a thermally conductive laminated film member, wherein a thermally conductive laminated film formed by laminating a thermally conductive layer and a strain relaxation layer is processed by reactive ion etching,
Graphite is selected as the material constituting the heat conductive layer, and any of amorphous Si, amorphous Ge, amorphous SiGe, amorphous SiO ₂ , amorphous SiO x, amorphous TiO ₂ , and combinations thereof is used as the material constituting the strain relaxation layer. Select
Using an oxygen-containing gas that etches the thermal conductive layer, a sulfur-fluorine compound-containing gas that etches the strain relaxation layer, and a fluorocarbon compound-containing gas that protects the etched surface, the at least three kinds of gases are switched. While applying etching in the order of the sulfur-fluorine compound-containing gas, the oxygen-containing gas, and the fluorocarbon compound-containing gas, a protective film is formed on a processing wall during the etching using the fluorocarbon compound-containing gas, and the protection A film is left after the etching using the sulfur-fluorine compound-containing gas and the etching using the oxygen-containing gas, and the film is processed to penetrate the heat-conducting laminated film, and the method for producing a heat-conducting laminated film member .   The method for producing a thermally conductive laminated film member according to claim 1, wherein the thermal conductive layer and the strain relaxation layer are alternately laminated one by one or a plurality of layers.   3. The method for manufacturing a heat conductive laminated film member according to claim 1, wherein the heat conductive layer and the strain relaxation layer each have a thickness of 1 nm to 20 nm.   When processing by the reactive ion etching is performed in the process chamber, when supplying any one of oxygen-containing gas, sulfur-fluorine compound-containing gas, fluorocarbon compound gas, or a combination thereof, The method for producing a thermally conductive laminated film member according to claim 1, wherein the supply amount is 100 sccm or less. 5. The method according to claim 1, wherein O ₂ is used as the oxygen-containing gas, SF ₆ is used as the sulfur-fluorine compound-containing gas, and C ₄ F ₈ is used as the fluorocarbon compound. The manufacturing method of the heat conductive laminated film member of this. A heat conductive laminated film member comprising a heat conductive layer and a strain relaxation layer, and having a processed structure part penetrating the heat conductive layer and the strain relaxation layer,
The processing unit wall surface of the processing structure has irregularities,
The thermally conductive layer is made of graphite, and the strain relaxation layer is made of amorphous Si, amorphous Ge, amorphous SiGe, amorphous SiO ₂ , amorphous SiO x, amorphous TiO ₂ , or a combination thereof,
The processed structure has a hole shape having an opening shape other than a circle, a groove shape, or a patterned notch shape,
The processing structure of the groove along the direction toward the heat dissipating member connected to the heat conductive laminated film member on the heat conductive laminated film member excluding the position of the heat conductive laminated film member corresponding to the place where the element is disposed The heat conductive laminated film member characterized by the above-mentioned.   The heat conductive laminated film member according to claim 6, which has a taper in the vicinity of an outer surface of the processed structure portion.   The layer thickness of the said heat conductive layer and the distortion relaxation layer is 1 nm or more and 20 nm or less, respectively, The heat conductive laminated film member of Claim 6 or 7 characterized by the above-mentioned.   The heat conductive laminated film member according to any one of claims 6 to 8, wherein the number of laminations of the processed structure portion penetrating the heat conductive layer and the strain relaxation layer is 2 or more and 4000 or less. .   10. The heat conductive laminated film member according to claim 6, wherein a processing width of a processing structure portion that penetrates the heat conductive layer and the strain relaxation layer is 100 nm or more and 300 μm or less.   It is a heat radiating component which combined the heat conductive laminated film member and heat radiating member of any one of Claims 6-10, Comprising: A part of said heat radiating member is made into the penetration process structure part of the said heat conductive laminated film member. A heat dissipating component characterized by the arrangement of   A heat dissipating device comprising the heat dissipating component according to claim 11 and an element. The thermally conductive laminated film member according to any one of claims 6 to 10, joined to a silicon substrate, a semiconductor element mounted on the silicon substrate, and heat generated by the semiconductor element via the thermally conductive laminated film member. And a heat spreader that accepts the heat and releases the heat to the outside,
A non-circular cross-sectional via hole penetrating the silicon substrate and the heat conductive laminated film is formed, and a heat conductive via post is embedded in the via hole, and the heat conductive laminated film is disposed in a plane direction through the via post. An LSI characterized by having a structure for transferring transmitted heat to the heat spreader.   A large number of bonded bodies of the silicon substrate and the thermally conductive laminated film are stacked, and via posts are provided in continuous via holes passing through the stacked multilayered bodies, and the via posts transfer heat to the heat spreader. The LSI according to claim 13 connected.