TW578264B - Structure for improving voiding in metal interconnects - Google Patents

Abstract

A structure for improving voiding in metal interconnects is disclosed. A metal material is added into a connection area of a wide line and a narrow line, for modifying the sharp turning corners of the two wide and narrow lines. This could reduce the local thermal stress gradient. Besides, a dummy slot is added in the wide line, and located in front of the necking region connecting with the narrow line, for stemming and lengthening the pathway leading the vacancy into the extended narrow line. By reducing the moving rate of vacancy, the disadvantages resulting from voiding are improved.

Description

578264 V. Description of the invention (1) Technical field to which the invention belongs: The present invention relates to integrated circuit manufacturing processes, and in particular, to improving the structure of pores generated by metal wiring. ° Previous technology: Semiconductor chips are used in a wide range of areas, such as laptop computer components, wireless communication components, desktop computers, and digital cameras. These semiconductor chips can contain many logic and memory elements. The fabrication of a semiconductor device 'uses an interconnect process to form a multilayer circuit structure. A four-line interconnection process uses a metal deposition step and a lithography step to form the element. FIG. 1 is a schematic side sectional view of multiple interconnects in a general integrated circuit component. Please refer to FIG. 1. First, a dielectric layer 14 is formed on a substrate ι by a chemical vapor deposition (CVD) step, and a position of a metal wiring is defined on the dielectric layer 14 by a lithography step. Then, a part of the dielectric layer at these positions is removed, and then a patterned metal layer 1 2 ′ is also formed by a deposition method to form a first-layer metal connection. Next, the same deposition and definition method is used to form a metal plug (Plug) 16 and a metal layer 20, where the metal plug 16 is used to connect two metal wires, and the metal layer 20 is another layer. Metal wiring. In addition, the dielectric layer 14, the dielectric layer 18, and the dielectric layer 22 used for isolation can be referred to as inter-metal dielectrics (inter-metal dielectrics) or inter-layer dielectrics (inter-layer dielectrics).

Page 5 5. Description of the invention (2) Repeat the above steps to form multiple layers of interconnect structures. Nowadays, integrated circuits are developing toward reducing connection widths, feature pattern sizes, and increasing connection densities, and how to increase the speed of component operation in integrated circuit components is always a must-have point for everyone. : Important requirements when choosing. Therefore, the use of copper metal materials as the connection structure has been developed to achieve the purpose of improving the speed of component operation. However, the process of using copper metal as a multiple interconnect material has found that pressure-induced pores (Stress_lnduced

Voiding; SIV) phenomenon. The porosity caused by pressure is very different from the thermal expansion coefficient between the interconnect and the substrate and the dielectric layer. The thermal expansion coefficient of metal materials is several times larger than that of silicon materials and dielectric materials. Therefore, the heating and cooling cycles In the manufacturing process, due to the shrinkage coefficient of gold and silicon materials and dielectric materials larger than the surrounding, the metal) = down, when the metal material is stressed in some directions =: move in the direction of = to release the stress. But suffer? : The Hajj is not stressed. The metal wire surrounded by it cannot move and is released. The hafnium substrate and the dielectric material form a void (Vo i d i ng). These pores will

Electro-migration), the migration, hole electron migration (Void these interconnected junctions, the pores appearing in the structure, gathered in ^. In a small case, the impact on circuit conduction is not: the line width is not so narrow The reduction of the width has caused the migration and aggregation of pores, but now with the line problem. Serious problems of circuit failure V. Description of the invention (3) Summary of the invention In view of the above, the small circuit element # 3 In the operation, metal wiring The generation of pores in the line width tends to provide = Therefore, the purpose of the present invention is to reduce the number of pores in the second metal region from the first metal region to the second region. Χ With the above purpose, the present invention This is a modification to the structure of the pores generated by the metal σ metal connection, so that the corner of the junction of the Ku Li ί: area connection is made-chamfered:---the rate of metal in the metal area The structure domain is connected to the second metal region; the first metal f of the first-metal region is cautious. Straight and the width of the first metal region is smaller than that of the second region, and a third metal. The area is on the side of the second gold ^ and this The three metal region is connected to the second metal region. The spear metal & field and another structure disclosed in the present invention, the #s, x # connected by Sun Mingshi are connected to the large region and the small region. The position of the connection is not to add a region made of non-metallic materials (S 1 0t), change the stress field to make the gold layer material low, this structure includes:-the first metal = rate: the second metal area is connected, t and the The width of the second metal region is less than the width of the first metal region; and, the slit located in the first region @ wherein the above-mentioned slit is located in the first metal region ^ :? A second metal region is connected to one end 'Constructed by an insulating material' and utilizing the virtual structure of the present invention 'can change the stress field of a metal material to make gold

Page 7 578264 V. Description of the invention (4) $ = The rate of pore movement in the material is reduced to improve the degree of pore aggregation and increase the thermal cycle life of circuit components. Implementation method: FIG. 2 shows a schematic diagram of a general metal layer structure. Please refer to Section 2 ® The metal layer 12 is a convex area, and its protruding end is the metal plug J16: connection position. It is mentioned in the background of the Ming that the metal layer 12 may have holes and gaps in the metal layer 12 due to the hot and cold cycling process. And, == metal itself is a granular structure, so many holes and seams exist in the metal layer 12 during the deposition process. These holes and slits are 2 to 4. ^ The relationship of the force is moved and aggregated, and the connection 16 and the two pores 24 as shown in Fig. 1 occur mostly at the convex end of the metal layer 12 and the metal insertion, which causes the problem of circuit failure. Therefore, the description of the present invention is more strongly connected with the structure that generates pores. In order to make the diagrams in Figures 6 to 6K as complete as possible, you can refer to the T column to describe and cooperate with the third one. Schematic invention Λ: In the structure of the metal line area 100 and _a of the present invention, it can be divided into the stress in the larger metal connection area 100. It belongs to the connection area 102. Because the metal connection area is shown by the metal Γ, the pores (not shown and accumulated θ) in the general metal material are accumulated in the metal connection area and the metal connection area 1.2 moves in the direction of the interface. Because: Ϊ: The end is connected to a metal plug (not shown). Therefore, the present invention is connected to the metal in the metal connection area 100.

Page 8 578264 V. Description of the invention (5) 102 The metal connection area 10 is added to the corner of the 102 connection, and adjacent sides of the metal connection area and the metal connection area 丨 〇〇 and the metal connection area 1 0 2 connected. The feature of this structure of the present invention is that the metal connection region 104 is added to reduce the stress gradient between the metal connection region 100 and the metal connection region 102, so that the purpose of reducing the pore movement rate can be achieved. In a preferred embodiment of the present invention, the shape of the metal connecting region 4 is an equilateral corner, as shown in FIG. 3. However, the above-mentioned shape of the metal connection area of the equilateral triangle with a 45-degree hypotenuse is only an example, and the metal connection area of a triangle with other hypotenuse angles such as Example 60 degrees 4 :, "= for example Any of the metal wiring regions 104 of the square 7 shape can be applied in the present invention, and the present invention is not limited thereto. In addition to the above-mentioned structure, the present invention further discloses another structure, which may also have the effect of improving the pores caused by the connection. Please refer to FIG. 4, which is a schematic diagram of the upper layer of the Erfayue metal layer structure. According to the present invention, the two metal layer junctions are divided into two parts like 02 to form a larger metal connection area 200 and a smaller metal 2 = 202, and the pores (not shown) pass from the metal connection area 200 to The square of the metal connection area 202 is 9 m. 4 + A and moves in white. Therefore, in the present invention, the position 2 where the metal connection region 202 is connected to the metal connection region 202, and the f region 204. The material of this slit area 204 is not acceptable: two, ZU4 can be connected with the surrounding metal to make you enter the Siwangze gate; 1 is manufactured simultaneously in the process of electric layer deposition, and it is also used to make metal The layer pre-construction 阊 安 * ^ # 1 X disease A Μ pre-patterning, the position of the slit region 204 is retained so that it is not filled with subsequent metal materials. Set

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f In the preferred embodiment of the car of the present invention, due to the manufacturing process, the depth of the slit 2⑽ is the same as the depth of the metal connection area 200, but this is only an example, and the present invention is limited to this. It is worth noting that there is a slit in the metal connection area 2000 of FIG. 4 as an example. Depending on the process and actual needs, other numbers of slits are formed in the metal connection area 200. The present invention does not Limited to this. For example, in another embodiment of the present invention, two narrow slits 204 that are narrower than those in FIG. 4 are formed in the metal connection region, as shown in FIG. 5. In addition, the shape of the slit 204 may be, as shown in FIG. 4 and FIG. 5, the interface that is relatively long and slender, and the metal connection area 202 may also be as shown in FIG. Cover the interface of metal wiring area 202. When the shape of the slit 204 is slender as shown in Figures 4 and 5, since the slit 20 * broadcasts the movement path of the pore repairing to the metal connection area 202, the pore will bypass the slit. 204 moves toward the metal wiring region 202. Due to the growth of the pore movement path, the accumulation of pores at the end of the metal connection area 202 and the contact surface of the metal plug can be improved, and the life of the device can be increased. In addition, when the shape f of the slit 204 is as wide and narrow as shown in FIG. 6, because the two slits "彳 can separate the pores above and below the gold connection area 200, only the two slits 2 The pores between 〇4 are easier to move into the metal wiring area 202, so it is easier to mitigate the fact that the pores of the entire metal wiring area 202 are easily moved into the metal wiring area 002. 0 This also achieves the problem of improving the failure of the circuit due to the pores. 0, the structure of this month, when the position of the slit 204 is located in the metal connection area 200 ^, and the metal connection area 200 is close to the metal connection. One end of the line area 202 should have the same effect. Therefore, the present invention is not limited to the

Page 10 V. Description of the invention (7) = shape, length, size, area, etc., can be set according to actual needs. In addition, the connection of a large metal connection area to an area is just an example. In the actual process and product Medium, connected to several small metal connection areas ..., the number of this metal connection area. Therefore, it is possible to improve the production of holes in the metal wiring by increasing the virtual junction of the above-mentioned metal cutting slits of the present invention between each of the large gold = connection areas 4: In the example, the copper metal interconnect structure as shown in Figure 3, Figure • or Figure 6 above can be formed in the circuit element, which can make the circuit a # · == 5: about 50,000 hours of baking Test the effect of pores caused by metal wiring in parts. The quality of circuit components is improved by not only Ming, Γ i: improvement. However, this question asks about the metal wiring materials, other metal wiring The wire material generates pores 2. The temple can also be improved by using the structure of the present invention. The present invention is not limited to those skilled in the art. The above description is only a comparison of the present invention, and is not an example of bismuth. The scope of patent application of the present invention; any equivalent alterations made without departing from the spirit disclosed by the present invention shall be included in the scope of patent application described below. 578264 The diagram briefly illustrates the preferred embodiment of the present invention A more detailed explanation will be supplemented by the following graphics Among them: FIG. 1 shows a schematic side sectional view of multiple interconnects in a general integrated circuit element, and FIG. 2 shows an upper schematic view of a general metal layer structure; FIG. 3 shows a metal of the present invention. The upper schematic view of the first embodiment of the layer structure; FIG. 4 illustrates the upper schematic view of the second embodiment of the metal layer structure of the present invention; FIG. 5 illustrates the third implementation of the metal layer structure of the present invention The upper schematic view of the example; and FIG. 6 is the upper schematic view of the fourth embodiment of the metal layer structure of the present invention. 0 Drawing number comparison description: 10 substrate 12 metal layer 14 dielectric layer 16 metal plug 18 dielectric layer 20 Metal layer 22 Dielectric layer 24 Aperture 100 Metal connection area 102 Metal connection area 104 Metal connection area 200 Metal connection area 202 Metal connection area 204 Slit area

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Claims (1)

578264 6. Scope of patent application 1. A structure for improving pores generated by a metal connection, including at least: a first metal region; at least a second metal region, wherein one end of the at least one second metal region is connected to the first metal Regions are connected, and the width of the at least one second metal region is smaller than the width of the first metal region; and at least one third metal region, wherein the at least one third metal region is located in the at least one second metal region One side, and the at least one third metal region is connected to the first metal region and the at least one second metal region. 2. The structure for improving the pore generation of the metal connection as described in item 1 of the scope of the patent application, wherein the shape of the third metal region is a triangle. 3. The structure for improving porosity of a metal connection as described in item 1 of the scope of the patent application, wherein the two sides of the above-mentioned at least one second metal region have a symmetrical one to the at least one third metal region, respectively. 4. The structure for improving porosity of a metal connection as described in item 1 of the scope of the patent application, further comprising a metal plug at the other end of the at least one second metal region. 5. The structure for improving porosity of a metal connection as described in item 1 of the scope of patent application, wherein the first metal region, the at least one second metal region, and the at least one third metal region are made of copper . Page 13 578264 VI. Application for Patent Scope 6-A kind of improved metal connection to generate pores-first metal region; <,, "冓, to) include: at least one second metal region, wherein the at least one is related to the first A metal region is connected, and the degree of one end of the at least one = domain is smaller than the width of the first metal region. R-The width of the i-region is at least one slit is located in the first metal region i to i to the smallest. It is located at the end of the -metal region and the at least one second metal seam system, and the slit is made of -non-metal material. Then — 7: the improvement of the metal connection as described in the first paragraph of the paragraph f to generate pores The slits described in No. 2 are-slender and cover the at least-the interface between the 'second / subordinate area and the first metal area.-8 The improved metal connection as described in item ΠίΓΓ1 generates pores. In the structure, the above-mentioned slit is a wide and narrow shape. As described in the item i of the patent application, the structure for improving the pore generation of the metal connection line further includes a metal plug at the at least one second gold end. Improved metal as described in item 1 of the patent Line generating structure aperture, the first metal region which t and the at least one second metal region is composed of lines of the above copper metal. 578264 Six patent application scopes --- _______ 11 ・ Improved structure as described in item i of the patent application scope ', where the above-mentioned slits are made of dielectric materials: raw holes, p.12, a integrated circuit structure, At least includes: a conductor structure, which is suitable for connecting the integrated circuit, the conductor structure is composed of a plurality of wires with different widths, components, and components; and a virtual structure, It is applicable to the conductor structure to reduce the number of pores moved by a one-to-two wire, wherein the width of the first to the second wire. I degree is large 1 3 · The integrated circuit structure described in item 12 of the patent application scope, wherein the conductor structure is made of copper metal. V 1 4 · The integrated circuit structure described in item 12 of the scope of patent application, further comprising a metal plug on the second wire. 15. The integrated circuit structure described in item 12 of the scope of the patent application, wherein the above-mentioned virtual structure is composed of conductive material and the function of the virtual structure is used to slow down the first wire to the second The width of the line varies. 16 · According to the integrated circuit structure described in item 1 of the patent application, the above-mentioned virtual structure is located on one side of the second wire, and is connected to the first wire and the second wire. Page 15 578264 VI. Scope of Patent Application 17 • The integrated circuit structure described in item 15 of the scope of patent application, wherein the above-mentioned virtual structure is composed of copper metal. 1 8 · The integrated circuit structure described in item 12 of the scope of the patent application, wherein the above-mentioned virtual structure is composed of a non-metal material, and the function of the virtual structure is to block the pores in the conductor structure from reaching the The direction of the second wire moves. 19. The integrated circuit structure described in item 17 of the scope of patent application, wherein the virtual structure is a slit in the conductor structure. 2 〇 The integrated circuit structure described in item 19 of the scope of patent application, wherein the slits are elongated. 2 1 · The integrated circuit structure described in item 17 of the scope of patent application, wherein the slits are made of a dielectric material.