This disclosure relates generally to semiconductor device packaging, and more specifically, to a semiconductor device with a redistribution layer and method of forming the same.
Today, there is an increasing trend to include sophisticated semiconductor devices in products and systems that are used every day. These sophisticated semiconductor devices may include features for specific applications which may impact the configuration of the semiconductor device packages, for example. For some features and applications, the configuration of the semiconductor device packages may be susceptible to lower reliability, lower performance, and higher product or system costs. Accordingly, significant challenges exist in accommodating these features and applications while minimizing the impact on semiconductor devices' reliability, performance, and costs.
The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.
Generally, there is provided, a semiconductor device with a redistribution layer. The semiconductor device includes a first non-conductive layer formed over a top passivation layer of a semiconductor die. The first non-conductive layer is patterned to form a collar structure surrounding an outer perimeter of an opening that exposes a top surface portion of a bond pad of the semiconductor die. The collar structure has an inner portion that contacts an outer region of the exposed bond pad surface and an outer portion that extends beyond the outer perimeter of the opening. The semiconductor device further includes a second non-conductive layer formed over the collar structure and exposed surface of the top of the semiconductor die. The second non-conductive layer is formed having a different formulation that that of the first non-conductive layer. For example, the first non-conductive layer may be formulated without sulfur or sulfur-based solvents (e.g., dimethyl sulfoxide). The second non-conductive layer is patterned to expose the top surface portion of the bond pad and inner sidewalls of the of the collar structure surrounding the opening. The collar structure is configured to prevent the second non-conductive layer from directly contacting the top surface of the bond pad. A conductive redistribution layer is formed over the patterned second non-conductive layer and exposed top surface of the bond pad such that a portion of an interconnecting trace is directly connected to the bond pad through the opening. By forming the redistribution layer bond pad connection with the surrounding collar structure in this manner, the semiconductor device can operate at higher voltages and exhibit superior reliability.
The semiconductor die 202 is configured and arranged in an active side up orientation. The bond pad 204 at the active side is configured for connection to printed circuit board (PCB) by way of a redistribution layer, under-bump structure, and conductive connectors formed at subsequent stages, for example. The semiconductor die 202 may be formed from any suitable semiconductor material, such as silicon, germanium, gallium arsenide, gallium nitride, silicon nitride, silicon carbide, and the like. The semiconductor die 202 may further include any digital circuits, analog circuits, RF circuits, power circuits, memory, processor, MEMS, sensors, the like, and combinations thereof.
The collar structure 312 is configured to surround an outer perimeter region of the bond pad 204. The collar structure 312 has an inner portion that directly contacts the top surface of the bond pad 204 and an inner sidewall 310 that surrounds the opening 304 exposing the top surface portion of the bond pad 204. An outer portion of the collar structure 312 may extend beyond an outer perimeter of the bond pad. The outer portion of the collar structure 312 which overlaps the passivation layer 208 of the semiconductor die 202 is configured to have a predetermined thickness dimension 308 measured from the top surface of the collar structure 312 to the top surface of the passivation layer 208. The collar structure 312 is further configured to have a predetermined width dimension 306 measured from the inner sidewall 310 to the outer perimeter of the collar structure 312. In this embodiment, the predetermined thickness dimension 308 is approximately equal to or greater than 5 microns and the predetermined width dimension 306 is approximately in a range of 5 microns to 20 microns.
The non-conductive layer 402 is patterned to form an opening through the non-conductive layer 402 such that the opening 304 is void of the non-conductive layer 402. The patterned opening through the non-conductive layer 402 is located directly over the bond pad 204 such that the substantial portion of the top surface of the bond pad 204 and inner sidewalls 310 of the of the collar structure 312 remain exposed. After the opening through the non-conductive layer 402 is formed, the collar structure 312 serves as an isolation barrier preventing the non-conductive layer 402 from directly contacting the top surface of the bond pad 204.
In this embodiment, a portion of the non-conductive layer 402 covers a top surface portion and outer sidewall portion of the collar structure 312. The portion of the non-conductive layer 402 which overlays the passivation layer 208 of the semiconductor die 202 is configured to have a predetermined thickness dimension 404 measured from the top surface of the non-conductive layer 402 to the top surface of the passivation layer 208. In this embodiment, the non-conductive layer 402 may be characterized as a thick dielectric layer having the predetermined thickness 404 approximately equal to or greater than 8 microns.
In this embodiment, the RLD 502 is patterned to form a plurality of RDL interconnection traces such as RDL interconnection trace 510 depicted in
Generally, there is provided, a method including forming a first non-conductive layer over a top side a semiconductor die; patterning the first non-conductive layer to form a collar structure surrounding an opening exposing a top surface of a bond pad of the semiconductor die; forming a second non-conductive layer over the first non-conductive layer and exposed portions of the top side of the semiconductor die, the second non-conductive layer different from the first non-conductive layer; patterning the second non-conductive layer to expose the top surface of the bond pad and inner sidewalls of the of the collar structure surrounding the opening such that the second non-conductive layer does not contact the bond pad; and forming a metal redistribution layer (RDL) over the second non-conductive layer and exposed top surface of the bond pad. The first non-conductive layer may be characterized as a polyimide material formulated without sulfur. The RDL may be characterized as a thick metal RDL having a thickness approximately equal to or greater than 8 microns. The collar structure surrounding the opening may have an inner portion that directly contacts the top surface of the bond pad and an outer portion that extends beyond an outer perimeter of the bond pad. A portion of the collar structure formed over a passivation layer of the semiconductor die may have a thickness approximately equal to or greater than 5 microns. The forming the RDL may include forming a plurality of patterned RDL interconnection traces, a first RDL interconnection trace of the plurality includes a first portion directly connected to the top surface of the bond pad. The method may further include forming an under-bump metallization (UBM) structure on a second portion of the first RDL interconnection trace, the UBM structure conductively interconnected with the bond pad by way of the first RDL interconnection trace. The forming the RDL may include forming the RDL by way of sputtering or electroplating a copper material. The second non-conductive layer may be formed having a thickness greater than that of the first non-conductive layer.
In another embodiment, there is provided, a semiconductor device including a collar structure formed from a first non-conductive material, the collar structure surrounding an opening exposing a top surface of a bond pad of a semiconductor die; a second non-conductive material formed as a layer covering the collar structure and the top side of the semiconductor die, the second non-conductive material different from the first non-conductive material; an opening through the second non-conductive layer exposes the top surface of the bond pad and inner sidewalls of the of the collar structure surrounding the opening such that the second non-conductive layer does not contact the bond pad; and a metal redistribution layer (RDL) formed over the second non-conductive layer and exposed top surface of the bond pad. The RDL may include a plurality of RDL interconnection traces, a first RDL interconnection trace of the plurality having a first portion directly connected to the top surface of the bond pad and an under-bump metallization (UBM) structure formed on a second portion of the first RDL interconnection trace, the UBM structure conductively interconnected with the bond pad by way of the first RDL interconnection trace. The collar structure may have an inner portion that directly contacts the top surface of the bond pad and an outer portion that extends beyond an outer perimeter of the bond pad. The collar structure may serve as an isolation barrier that prevents the second non-conductive layer from directly contacting the top surface of the bond pad. The RDL may be characterized as a thick metal RDL having a thickness approximately equal to or greater than 8 microns. The second non-conductive material may be characterized as a polyimide material having a substantially planar top surface.
In yet another embodiment, there is provided, a method including forming a first non-conductive layer over a top side a semiconductor die; patterning the first non-conductive layer to form a collar structure surrounding an opening exposing a top surface of a bond pad of the semiconductor die; forming a second non-conductive layer over the first non-conductive layer and exposed portions of the top side of the semiconductor die, the second non-conductive layer having a mechanical property different from that of the first non-conductive layer; patterning the second non-conductive layer to expose the top surface of the bond pad and inner sidewalls of the of the collar structure surrounding the opening such that the second non-conductive layer does not contact the bond pad; and forming a metal redistribution layer (RDL) over the second non-conductive layer and exposed top surface of the bond pad. The forming the RDL may include forming a plurality of patterned RDL interconnection traces, a first RDL interconnection trace of the plurality having a first portion directly connected to the top surface of the bond pad. The method may further include forming an under-bump metallization (UBM) structure on a second portion of the first RDL interconnection trace, the UBM structure conductively interconnected with the bond pad by way of the first RDL interconnection trace. The collar structure may have an inner portion that directly contacts the top surface of the bond pad and an outer portion that extends beyond an outer perimeter of the bond pad, the collar structure configured to serve as an isolation barrier preventing the second non-conductive layer from directly contacting the top surface of the bond pad. The mechanical property may be characterized as an elongation property, the second non-conductive layer having an elongation property higher than that of the first non-conductive layer.
By now, it should be appreciated that there has been provided a semiconductor device with a redistribution layer. The semiconductor device includes a first non-conductive layer formed over a top passivation layer of a semiconductor die. The first non-conductive layer is patterned to form a collar structure surrounding an outer perimeter of an opening that exposes a top surface portion of a bond pad of the semiconductor die. The collar structure has an inner portion that contacts an outer region of the exposed bond pad surface and an outer portion that extends beyond the outer perimeter of the opening. The semiconductor device further includes a second non-conductive layer formed over the collar structure and exposed surface of the top of the semiconductor die. The second non-conductive layer is formed having a different formulation that that of the first non-conductive layer. For example, the first non-conductive layer may be formulated without sulfur or sulfur-based solvents. The second non-conductive layer is patterned to expose the top surface portion of the bond pad and inner sidewalls of the of the collar structure surrounding the opening. The collar structure is configured to prevent the second non-conductive layer from directly contacting the top surface of the bond pad. A conductive redistribution layer is formed over the patterned second non-conductive layer and exposed top surface of the bond pad such that a portion of an interconnecting trace is directly connected to the bond pad through the opening. By forming the redistribution layer bond pad connection with the surrounding collar structure in this manner, the semiconductor device can operate at higher voltages and exhibit superior reliability.
The terms “front,” “back,” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.
Although the invention is described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.
Furthermore, the terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles.
Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.