TWI476845B - Bump process and its structure - Google Patents

Description

Bump process and its structure

The present invention relates to a bump process, and more particularly to a bump process for improving product yield.

When the volume of electronic products is lighter, thinner, shorter, and smaller, the layout of internal circuits is relatively denser. Therefore, the distance between adjacent electrical connection elements in the internal circuit cannot reach the short-circuit safe distance range, which is easy to cause A short circuit occurs.

The main object of the present invention is to provide a bump process comprising providing a germanium substrate having a surface, a plurality of pads disposed on the surface, and a protective layer disposed on the surface, the protective layer And having a plurality of openings, wherein the openings expose the pads; forming a titanium-containing metal layer on the germanium substrate, the titanium-containing metal layer covering the protective layer and the pads, and the titanium-containing metal layer Having a plurality of first regions and a plurality of second regions outside the first regions; forming a first photoresist layer on the titanium-containing metal layer; patterning the first photoresist layer to form a plurality of first regions Slotting, the first slots are corresponding to the first regions of the titanium metal layer; forming a plurality of copper bumps on the first slots, each of the copper bumps having a first top surface and a first ring wall; the first photoresist layer is removed to expose the first top surfaces of the copper bumps, the first ring walls, and the second regions of the titanium-containing metal layer; a second photoresist layer on the titanium-containing metal layer and covering the copper bumps; patterning the second photoresist layer to form A plurality of second slot, each of the second slot corresponding to each of the lines and each copper bump The second slot has an inner side wall, and a space is formed between the inner side wall of each of the second slots and the first ring wall of each of the copper bumps; a plurality of bump isolation layers are formed on the second slot a space, a first top surface of each of the copper bumps, and the first ring wall, and each of the bump isolation layers has a second top surface; forming a plurality of bonding layers on the bump isolation layers a second top surface; removing the second photoresist layer; and removing the second regions of the titanium-containing metal layer such that each of the first regions of the titanium-containing metal layer is formed as a copper bump The underlying metal layer under the bump. Since each of the bump isolation layers covers the first ring wall and the first top surface of each of the copper bumps, the copper ions of the copper bumps are prevented from being detached, thereby causing an electrical short circuit. The distance between adjacent copper bumps can be further reduced to increase the circuit wiring density.

Referring to FIGS. 1 and 2A to 2L, which are a preferred embodiment of the present invention, a bump process system includes the following steps: First, referring to steps 10 and 2A of FIG. 1, a substrate 110 is provided. The cymbal substrate 110 has a surface 111, a plurality of pads 112 disposed on the surface 111, and a protective layer 113 disposed on the surface 111. The protective layer 113 has a plurality of openings 113a, and the openings 113a are The solder pads 112 are exposed; then, referring to steps 11 and 2B of FIG. 1 , a titanium-containing metal layer 200 is formed on the germanium substrate 110, and the titanium-containing metal layer 200 covers the protective layer 113 and the solders Pad 112, and the titanium-containing metal layer 200 has a plurality of first regions 210 and a plurality of second regions 220 located outside the first regions 210; thereafter, refer to steps 12 and 2C of FIG. 1 to form A first photoresist layer 300 is disposed on the titanium-containing metal layer 200; then, referring to steps 13 and 2D of FIG. 1, the first photoresist layer 300 is patterned to form a plurality of first layers. Slotting 310, the first trenches 310 are corresponding to the first regions 210 of the titanium metal layer 200; afterwards, referring to steps 14 and 2E of FIG. 1, a plurality of copper bumps 120 are formed thereon. Each of the first bumps 310 has a first top surface 121 and a first ring wall 122. Next, refer to steps 15 and 2F of FIG. 1 to remove the first photoresist. The layer 300 is used to expose the first top surfaces 121 of the copper bumps 120, the first ring walls 122, and the second regions 220 of the titanium-containing metal layer 200; afterwards, please refer to FIG. In steps 16 and 2G, a second photoresist layer 400 is formed on the titanium-containing metal layer 200 and covers the copper bumps 120.

Next, referring to steps 17 and 2H of FIG. 1 , the second photoresist layer 400 is patterned to form a plurality of second trenches 410 , each of the second trenches 410 corresponding to each of the copper bumps 120 and each The second slot 410 has an inner side wall 411. A space S is formed between the inner side wall 411 of each of the second slots 410 and the first ring wall 122 of each of the copper bumps 120. Referring to steps 18 and 2I of FIG. 1 , a plurality of bump isolation layers 130 are formed in the spaces S, the first top surface 121 of each of the copper bumps 120, and the first ring wall 122, and each of the protrusions The block isolation layer 130 has a second top surface 131. In this embodiment, the material of the bump isolation layer 130 is selected from one of nickel, palladium, gold or an alloy of the above metals; In the steps 19 and 2J of FIG. 1 , a plurality of bonding layers 140 are formed on the second top surfaces 131 of the bump isolation layers 130 , and the bonding layers 140 are made of gold; Steps 20 and 2K of the figure, the second photoresist layer 400 is removed; finally, please refer to steps 21 and 2L of FIG. 1 to remove the second regions 2 of the titanium-containing metal layer 200. 20, the first region 210 of the titanium-containing metal layer 200 is formed as a bump under metal layer 150 under each of the copper bumps 120, and a bump structure 100 is formed. The material of the under bump metal layer 150 is selected from one of titanium/tungsten/gold, titanium/copper or titanium/tungsten/copper. In this embodiment, each of the under bump metal layers 150 has a first The second ring wall 151 and the second ring wall 151 have a first outer circumference 151a, and each of the bump isolation layers 130 has a third ring wall 132 and the third ring wall 132 has a second outer circumference. The second outer circumference 132a is not smaller than the first outer circumference 151a, and the second annular wall 151 of each of the under bump metal layers 150 and the first annular wall 122 of each of the copper bumps 120 are In addition, the protective layer 113 further has a exposed surface 113b. Each of the bump isolation layers 130 further has a bottom surface 133. The exposed surface 113b and the bottom surface 133 have a gap G therebetween. In this embodiment, since the bump isolation layer 130 covers the first ring wall 122 and the first top surface 121 of each of the copper bumps 120, the copper ions of the copper bumps 120 can be prevented. The situation of being free causes an electrical short circuit, so the distance between adjacent copper bumps 120 can be further reduced to increase the circuit wiring density.

2L, which is a bump structure 100 according to a preferred embodiment of the present invention, comprising at least one germanium substrate 110, a plurality of under bump metal layers 150, and a plurality of copper bumps 120. The plurality of bump isolation layers 130 and the plurality of bonding layers 140 have a surface 111, a plurality of pads 112 disposed on the surface 111, and a protective layer 113 disposed on the surface 111. The protective layer The 113 series has a plurality of openings 113a and a exposed surface 113b, and the openings 113a expose the pads 112. The under bump metal layers 150 are formed on the pads 112, and the bumps are under the metal layer. The material of 150 is selected from one of titanium/tungsten/gold, titanium/copper or titanium/tungsten/copper, and the copper bumps 120 are formed on the under bump metal layer 150, and each of the copper bumps The block 120 has a first top surface 121 and a first annular wall 122. In this embodiment, each of the bumps is under The metal layer 150 has a second ring wall 151 and the second ring wall 151 has a first outer circumference 151a, and the second ring wall 151 of each of the under bump metal layers 150 and each of the copper bumps 120 The first ring wall 122 is flush, and the bump isolation layer 130 covers the first top surface 121 and the first ring wall 122 of each of the copper bumps 120, and each of the bump isolation layers 130 The second annular wall 132 has a second outer circumference 132a, and the second outer circumference 132a is not less than the metal under the bumps. The first outer circumference 151a of the second ring wall 151 of the layer 150, the exposed surface 113b of the protective layer 113 and the bottom surface 133 of each of the bump isolation layers 130 have a gap G, in this embodiment. The material of the bump isolation layer 130 is selected from one of nickel, palladium, gold or an alloy of the above metals. The bonding layers 140 are formed on the second tops of the bump isolation layers 130. The surface of the bonding layer 140 is gold.

The scope of the present invention is defined by the scope of the appended claims, and any changes and modifications made by those skilled in the art without departing from the spirit and scope of the invention are within the scope of the present invention. .

10‧‧‧ Provide a substrate

11‧‧‧ forming a titanium-containing metal layer on the germanium substrate, and the titanium-containing metal layer has a plurality of first regions and a plurality of second regions

12‧‧‧ forming a first photoresist layer on the titanium-containing metal layer

13‧‧‧ patterning the first photoresist layer to form a plurality of first trenches, the first trenches corresponding to the first regions containing a titanium metal layer

14‧‧‧ forming a plurality of copper bumps on the first slots, each of the copper bumps having a first top surface and a first ring wall

Removing the first photoresist layer to expose the first top surfaces of the copper bumps, the first ring walls, and the second regions of the titanium-containing metal layer

16‧‧‧ forming a second photoresist layer on the titanium-containing metal layer and covering the copper bumps

17‧‧‧ patterning the second photoresist layer to form a plurality of second slots, each of the second slots corresponding to each of the copper bumps and each of the second slotting portions having an inner sidewall, each of the a space is formed between the inner side wall of the two slots and the first ring wall of each of the copper bumps

18‧‧‧ forming a plurality of bump isolation layers in the spaces, the first top surface of each of the copper bumps, and the first ring wall

19‧‧‧ forming a plurality of bonding layers on the bump isolation layers

20‧‧‧Remove the second photoresist layer

21‧‧‧ removing the second regions of the titanium-containing metal layer such that the first regions of the titanium-containing metal layer are formed as a sub-bump metal layer

100‧‧‧bump structure

110‧‧‧矽 substrate

111‧‧‧ surface

112‧‧‧ solder pads

113‧‧‧Protective layer

113a‧‧‧ openings

113b‧‧‧ appearance

120‧‧‧ copper bumps

121‧‧‧First top surface

122‧‧‧First ring wall

130‧‧‧Bump isolation layer

131‧‧‧Second top

132‧‧‧ Third ring wall

132a‧‧‧Second outer perimeter

133‧‧‧ bottom

140‧‧‧Connection layer

150‧‧‧ under bump metal layer

151‧‧‧ Second ring wall

151a‧‧‧First outer perimeter

200‧‧‧Titanium-containing metal layer

210‧‧‧First District

220‧‧‧Second District

300‧‧‧First photoresist layer

310‧‧‧First slotting

400‧‧‧second photoresist layer

410‧‧‧Second slotting

411‧‧‧ inner side wall

G‧‧‧ gap

S‧‧‧ Space

Figure 1 is a flow chart showing a bump process in accordance with a preferred embodiment of the present invention.

2A to 2L are schematic cross-sectional views of the bump process in accordance with a preferred embodiment of the present invention.

10‧‧‧ Provide a substrate

11‧‧‧ forming a titanium-containing metal layer on the germanium substrate, and the titanium-containing metal layer has a plurality of first regions and a plurality of second regions

12‧‧‧ forming a first photoresist layer on the titanium-containing metal layer

13‧‧‧ patterning the first photoresist layer to form a plurality of first trenches, the first trenches corresponding to the first regions containing a titanium metal layer

14‧‧‧ forming a plurality of copper bumps on the first slots, each of the copper bumps having a first top surface and a first ring wall

Removing the first photoresist layer to expose the first top surfaces of the copper bumps, the first ring walls, and the second regions of the titanium-containing metal layer

16‧‧‧ forming a second photoresist layer on the titanium-containing metal layer and covering the copper bumps

17‧‧‧ patterning the second photoresist layer to form a plurality of second slots, each of the second slots corresponding to each of the copper bumps and each of the second slotting portions having an inner sidewall, each of the a space is formed between the inner side wall of the two slots and the first ring wall of each of the copper bumps

18‧‧‧ forming a plurality of bump isolation layers in the spaces, the first top surface of each of the copper bumps, and the first ring wall

19‧‧‧ forming a plurality of bonding layers on the bump isolation layers

20‧‧‧Remove the second photoresist layer

21‧‧‧ removing the second regions of the titanium-containing metal layer such that the first regions of the titanium-containing metal layer are formed as a sub-bump metal layer

Claims (7)

A bump process comprising: providing a substrate having a surface, a plurality of pads disposed on the surface, and a protective layer disposed on the surface, the protective layer having a plurality of openings And the openings are exposed to the pads; forming a titanium-containing metal layer on the germanium substrate, the titanium-containing metal layer covering the protective layer and the pads, and the titanium-containing metal layer has a plurality of first And a plurality of second regions located outside the first regions; forming a first photoresist layer on the titanium-containing metal layer; patterning the first photoresist layer to form a plurality of first trenches, a first groove corresponding to the titanium metal layer; a plurality of copper bumps are formed on the first slots, each of the copper bumps having a first top surface and a first ring wall; Removing the first photoresist layer to expose the first top surfaces of the copper bumps, the first ring walls, and the second regions of the titanium-containing metal layer; forming a second photoresist layer And covering the copper bumps; patterning the second photoresist layer to form a plurality of second trenches, each The second slot is corresponding to each of the copper bumps, and each of the second slots has an inner sidewall, and the inner sidewall of each of the second slots and the first annular wall of each of the copper bumps are formed. Forming a plurality of bump isolation layers in the spaces, the first top surface of each of the copper bumps, and the first ring wall, and each of the bump isolation layers has a second top surface; forming a plurality Bonding layers on the second top surfaces of the bump isolation layers; removing the second photoresist layer; The second regions of the titanium-containing metal layer are removed such that each of the first regions of the titanium-containing metal layer is formed as a sub-bump metal layer under each of the copper bumps. The bump process of claim 1, wherein the protective layer further has a exposed surface, each of the bump isolation layers further has a bottom surface, and the exposed surface and the bottom surface have a gap therebetween. The bump process of claim 1, wherein each of the under bump metal layers has a second ring wall and the second ring wall has a first outer perimeter, each of the bump isolation layers Another has a third annular wall and the third annular wall has a second outer perimeter, the second outer perimeter being no less than the first outer perimeter. The bump process of claim 1 or 3, wherein each of the under bump metal layers has a second ring wall, and each of the second ring walls and each of the first ring walls are flush . The bump process of claim 1, wherein the material of the under bump metal layer is selected from one of titanium/tungsten/gold, titanium/copper or titanium/tungsten/copper. The bump process of claim 1, wherein the material of the bonding layer is gold. The bump process of claim 1, wherein the material of the bump isolation layer is selected from the group consisting of nickel, palladium, gold or an alloy of the above metals.