CN111524818A - Electronic device and method of making the same - Google Patents

Abstract

The invention provides an electronic device and a manufacturing method thereof.A sacrificial anode is arranged below a bonding pad and extends to the edge of the device, so that the influence of the sacrificial anode on the bonding pad during heat treatment can be avoided, and the AlSi layer above the bonding pad can be protected by the sacrificial anode and prevented from being oxidized. The AlSi layer can increase the wettability of the wire bonding ball and ensure the solderability, and preferably, the AlSi layer has N doping which can ensure that Al is not oxidized.

Description

Electronic device and method of making the same

technical field

The invention relates to the field of manufacturing and testing of semiconductor devices, in particular to an electronic device and a manufacturing method thereof.

Background technique

The final step of chip formation often requires the deposition of interlayer insulating layers and wiring layers in subsequent processes. For conventional chips, it is often necessary to form pads for external electrical connections. The external electrical connection can be formed in a forward-chip or flip-chip manner, where it is necessary to ensure the reliability of the external electrical connection.

SUMMARY OF THE INVENTION

Based on solving the above problems, the present invention provides a manufacturing method of an electronic device, which includes the following:

(1) providing a substrate comprising at least one electrode;

(2) forming an insulating layer on the substrate and patterning to form a first opening exposing the electrode;

(3) forming a sacrificial anode layer and a wiring layer on the insulating layer, one end of the wiring layer is electrically connected to the electrode, and the other end is arranged on the sacrificial anode layer to form a pad;

(4) forming and patterning a passivation layer covering the insulating layer, the wiring layer and the sacrificial anode layer to form a second opening exposing the pad;

(5) forming an AlSi layer on the pad in the second opening;

(6) Wire bonding balls are formed on the AlSi layer.

Wherein, the AlSi layer is formed by a co-sputtering method of aluminum palladium and a silicon target, and the sputtering atmosphere at least contains nitrogen.

Wherein, forming the wire-bonding balls in step (6) further includes heating and melting the wire-bonding balls, so that the wire-bonding balls and the AlSi layer form an intermetallic compound layer.

The present invention also provides an electronic device, which is obtained by the above-mentioned manufacturing method of the electronic device, and specifically includes:

a substrate including at least one electrode;

an insulating layer disposed on the substrate and having a first opening exposing the electrode;

A sacrificial anode and a wiring layer are arranged on the insulating layer, wherein one end of the wiring layer is electrically connected to the electrode, and the other end is arranged on the sacrificial anode layer to form a pad;

a passivation layer covering the insulating layer, the wiring layer and the sacrificial anode layer and having a second opening exposing the pad;

An AlSi layer, disposed on the pad in the second opening;

Wire-bonded balls are disposed on the AlSi layer.

Wherein, an intermetallic compound layer is formed between the wire bonding ball and the AlSi layer.

Wherein, the sacrificial anode layer includes a first part that does not correspond to the top and bottom of the pad and a second part that corresponds to the top and bottom of the pad, the first part and the second part are integrally formed, and the first part is formed by The pad locations extend to the edge of the electronic device.

Wherein, the second part has a recess, and a part of the pad is located in the recess.

Wherein, the second part is an annular shape, and the annular shape has a third opening.

Wherein, the third opening is filled with insulating material.

Wherein, the pad has a notch conformal to the third opening.

The invention has the following beneficial effects: the sacrificial anode is arranged under the pad and extends to the edge of the device, which can avoid the influence of the sacrificial anode on the thermal treatment of the pad, and the sacrificial anode can protect the AlSi on the pad layer to prevent it from being oxidized. The arrangement of the AlSi layer can increase the wettability of the wire bonding ball and ensure its solderability, and preferably, the AlSi layer has N doping, which can ensure that the Al is not oxidized.

Description of drawings

1 is a cross-sectional view of an electronic device of the present invention;

2A is a cross-sectional view of a pad structure according to a first embodiment of the present invention;

2B is a top view of the sacrificial anode according to the first embodiment of the present invention;

3A is a cross-sectional view of a pad structure according to a second embodiment of the present invention;

3B is a top view of the sacrificial anode according to the second embodiment of the present invention;

4A is a cross-sectional view of a pad structure according to a third embodiment of the present invention;

4B is a top view of the sacrificial anode according to the third embodiment of the present invention;

5A is a cross-sectional view of a pad structure according to a fourth embodiment of the present invention;

5B is a top view of the sacrificial anode according to the fourth embodiment of the present invention;

6A is a cross-sectional view of a pad structure according to a fifth embodiment of the present invention;

6B is a top view of the sacrificial anode according to the fifth embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present disclosure.

Unless otherwise defined, technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. As used in this disclosure, "first," "second," and similar terms do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right", etc. are only used to represent the relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

The electronic device and the manufacturing method thereof according to the disclosed embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The specific formation method of the electronic device of the present invention includes:

(1) providing a substrate comprising at least one electrode;

(2) forming an insulating layer on the substrate and patterning to form a first opening exposing the electrode;

(3) forming a sacrificial anode layer and a wiring layer on the insulating layer, one end of the wiring layer is electrically connected to the electrode, and the other end is arranged on the sacrificial anode layer to form a pad;

(4) forming and patterning a passivation layer covering the insulating layer, the wiring layer and the sacrificial anode layer to form a second opening exposing the pad;

(5) forming an AlSi layer on the pad in the second opening;

(6) Wire bonding balls are formed on the AlSi layer.

Referring to FIG. 1, the electronic device of the present invention includes a substrate 10, which may be a silicon substrate. The substrate 10 includes an upper surface having an active area and an opposing lower surface having on the upper surface at least one electrode 11, which may be a metal electrode or a metal silicide electrode, which is electrically connected to the substrate 10 electronic chips.

Then, an insulating layer 12 is formed on the substrate 10. The insulating layer 12 can be formed by methods such as PVD, CVD, sputtering or atomic deposition, and the thickness of the insulating layer 12 is less than 100 microns. The insulating layer 12 can be an inorganic material, such as silicon nitride, silicon oxide, silicon oxynitride, etc., or an organic material, such as polyimide, acrylic material, and the like. A plurality of first openings are formed in the insulating layer 12 by patterning to expose the electrodes 11 . This patterning can be achieved by wet etching.

Next, a metal layer is deposited on the insulating layer 12, and the metal layer may be an alloy of any one of Mg, Ni, and Pd and Al, wherein the weight percentage of Al is greater than 50%. The metal layer is then patterned to form a sacrificial anode 13, which will be highlighted in the following sections.

Then, a wiring layer 15 is formed on the insulating layer 12, and the material of the wiring layer 15 is Al, which is a patterned structure. The wiring layer 15 is electrically connected to the electrode 11 , and extends from the electrode 11 on the insulating layer to a portion of the sacrificial anode 13 . Wherein, the part of the wiring layer 15 on the sacrificial anode 13 is an externally connected pad 15, and the pad 15 is within the projection of the sacrificial anode 13 and smaller than the sacrificial anode when viewed from above. 13 area.

Then, a passivation layer 17 is formed on the insulating layer 12 , the wiring layer 14 and the sacrificial anode layer 13 , the passivation layer 17 should be higher than the uppermost surface of the wiring layer 14 , and the passivation layer 17 is A patterned second opening is formed in layer 17, which should expose the pad. The passivation layer 17 may be silicon nitride or silicon oxide material.

An AlSi layer is formed on the pad 15 in the second opening, the AlSi layer is formed by a co-sputtering method of aluminum palladium and a silicon target, and the sputtering atmosphere at least contains nitrogen, such as pure nitrogen, Mixtures of nitrogen and hydrogen, etc. By sputtering in a nitrogen atmosphere, the AlSi layer can be doped with N element, which can prevent the oxidation of Al, that is, the oxidation of the Al pad 15 and the oxidation of Al in the AlSi layer.

Finally, wire bonding balls 16 are formed on the AlSi layer. The wire-bonding balls 16 may be alloys containing copper or aluminum, which are formed by heating and melting the above alloy materials, so that the wire-bonding balls 16 and the AlSi layer form an intermetallic compound layer, in which at least the intermetallic compound layer should be Including Al, Si and N elements, among which Si in the AlSi layer can increase the wettability of the wire bonding ball and ensure its solderability.

Referring to FIGS. 2A-6B , the pad structures and sacrificial anode structures of electronic devices in various embodiments are described below.

first embodiment

Referring first to FIG. 2A, there is a pad 15 on a sacrificial anode 13, the sacrificial anode 13 including a first portion 131 and a second portion 132, wherein the first portion 131 extends to the edge of the electronic device, and the second portion 132 is connected to the first part 131 and has a shape corresponding to the pad 15 .

Referring to FIG. 2B , the first part 131 may be a long strip, and the second part 132 may be a circle or a square, wherein the width of the first part 131 is smaller than the width of the second part 132 to disperse the current of the second part 132 . Moreover, when the second portion 132 is circular, the pad 15 is also circular, and when the second portion 132 is square, the pad is also square.

There is an AlSi layer 18 on the pad 15, and as mentioned above, the AlSi layer 18 should have N element, and the wire bonding ball 16 is formed on the AlSi layer 18, and when passing through a high temperature, the wire An intermetallic compound layer 19 is formed between the bonding balls 16 and the AlSi layer 18 .

Second Embodiment

3A and 3B, the structure of the sacrificial anode 13 is the same as that of the first embodiment, the difference is that there is a barrier layer 20 between the sacrificial anode 13 and the pad 15, and the barrier layer 20 is Ti/TiN Or Ta/TaN, etc., wherein the barrier layer 20 may completely cover the sacrificial anode 13 and may be partially formed on the insulating layer 12 . The barrier layer 20 can prevent the mutual diffusion between the sacrificial anode 13 and the pad 15 during operation.

Third Embodiment

Referring to FIGS. 4A and 4B , in this embodiment, the second portion 132 of the sacrificial anode 13 has a recess 21 , the recess 21 is in the shape of an arc surface, and the center area of the recess 21 is deeper and the edge area is shallower . A portion of the material of the pad 15 is embedded in the recess 21 . The recess 21 can disperse the current to the edge of the pad, thereby preventing the current in the central area of the pad 15 from being too large and preventing the current from being too concentrated.

Fourth Embodiment

5A and 5B, in this embodiment, the second portion 132 of the sacrificial anode 13 has a third opening 22, the third opening 22 is a circle, and the third opening 22 is filled with insulating material 23. The insulating material 23 can be made of the same material as the insulating layer 12, and can be formed in the same step.

Fifth Embodiment

Referring to FIGS. 6A and 6B , which is similar to the fifth embodiment, the second portion 132 of the sacrificial anode 13 has a third opening 22 , and the third opening 22 is circular. And a part of the pad 15 is embedded in the third opening 22, and the pad 15 has a notch 24 on the top surface of the pad 15 due to its conformal shape, and the bottom of the notch 24 has an intermetallic compound layer, the bottom of the wire bond ball 16 is disposed in the recess 24 .

In the present invention, the sacrificial anode is arranged under the pad and extends to the edge of the device, so that the influence of the sacrificial anode on the thermal treatment of the pad can be avoided, and the sacrificial anode can protect the AlSi layer on the pad from being oxidized. The arrangement of the AlSi layer can increase the wettability of the wire bonding ball and ensure its solderability, and preferably, the AlSi layer has N doping, which can ensure that the Al is not oxidized.

Finally, it should be noted that: obviously, the above-mentioned embodiments are only examples for clearly illustrating the present invention, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (10)

1. A manufacturing method of an electronic device, comprising the following: (1) providing a substrate comprising at least one electrode; (2) forming an insulating layer on the substrate and patterning to form a first opening exposing the electrode; (3) forming a sacrificial anode layer and a wiring layer on the insulating layer, one end of the wiring layer is electrically connected to the electrode, and the other end is arranged on the sacrificial anode layer to form a pad; (4) forming and patterning a passivation layer covering the insulating layer, the wiring layer and the sacrificial anode layer to form a second opening exposing the pad; (5) forming an AlSi layer on the pad in the second opening; (6) Wire bonding balls are formed on the AlSi layer. 2 . The method for manufacturing an electronic device according to claim 1 , wherein the AlSi layer is formed by a co-sputtering method of aluminum palladium and a silicon target, and the sputtering atmosphere at least contains nitrogen. 3 . 3 . The method for manufacturing an electronic device according to claim 1 , wherein forming the wire-bonding balls in step (6) further comprises heating and melting the wire-bonding balls, and making the wire-bonding balls and the AlSi layer forms an intermetallic compound layer. 4. An electronic device, obtained by the manufacturing method of the electronic device according to any one of claims 1-3, specifically comprising: a substrate including at least one electrode; an insulating layer disposed on the substrate and having a first opening exposing the electrode; A sacrificial anode and a wiring layer are arranged on the insulating layer, wherein one end of the wiring layer is electrically connected to the electrode, and the other end is arranged on the sacrificial anode layer to form a pad; a passivation layer covering the insulating layer, the wiring layer and the sacrificial anode layer and having a second opening exposing the pad; An AlSi layer, disposed on the pad in the second opening; Wire-bonded balls are disposed on the AlSi layer. 5. The electronic device according to claim 4, wherein an intermetallic compound layer is formed between the wire bonding ball and the AlSi layer. 6 . The electronic device according to claim 4 , wherein the sacrificial anode layer comprises a first portion not corresponding to the upper and lower sides of the pad and a second portion corresponding to the upper and lower portions of the pad, and the first portion A portion and a second portion are integrally formed, and the first portion extends from the pad location to the edge of the electronic device. 7 . The electronic device of claim 6 , wherein the second portion has a recess, and a portion of the pad is located in the recess. 8 . 8 . The electronic device according to claim 6 , wherein the second part is an annular shape, and the annular shape has a third opening. 9 . 9 . The electronic device according to claim 6 , wherein the third opening is filled with insulating material. 10 . 10. The electronic device of claim 6, wherein the pad has a notch conformal to the third opening.

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