SEMICONDUCTOR STRUCTURE FOR MEMS DEVICE

• US 20170369308A1
• Filed: 06/27/2016
• Published: 12/28/2017
• Est. Priority Date: 06/27/2016
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Liu, Yu-Chia, Chu, Chia-Hua, Cheng, Chun-Wen, Peng, Jung-Huei
• Granted Patent: US 10,160,639 B2
• Time in Patent Office: Days
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 2203/0785 Transfer and j oin technology, i.e. forming the electronic processing unit and the micromechanical structure on separate substrates and joining the substrates

Abstract

The present disclosure relates to a semiconductor structure for a MEMS device. In some embodiments, the structure includes an interlayer dielectric (ILD) region positioned over a substrate. Further the structure includes an inter-metal dielectric region. The IMD region includes a passivation layer overlying a stacked structure. The stacked structure includes dielectric layers and etch stop layers that are stacked in an alternating fashion. Metal wire layers are disposed within the stacked structure of the IMD region. The structure also includes a sensing electrode electrically connected to the IMD region with an electrode extension via. The structure includes a MEMS substrate comprising a MEMS device having a soft mechanical structure positioned adjacent to the sensing electrode.

Claims

1. A structure for a microelectromechanical systems (MEMS) device, the structure comprising:

an interlayer dielectric (ILD) region positioned over a substrate;

an inter-metal dielectric (IMD) region positioned over the ILD region, wherein the IMD region is comprised of a passivation layer overlying a stacked structure, wherein the stacked structure alternates between dielectric layers and etch stop layers, wherein an uppermost one of the etch stop layers abuts the passivation layer, and wherein metal wire layers are disposed within the stacked structure of the IMD region;

a sensing electrode electrically connected to the metal wire layers of the IMD region with an electrode extension via and abutting the passivation layer; and

a MEMS substrate comprising a MEMS device having a soft mechanical structure positioned adjacent to the sensing electrode.

2. The structure of claim 1, wherein the electrode extension via comprises tungsten.

3. The structure of claim 1, wherein the passivation layer is silicon nitride.

4. The structure of claim 1, wherein the etch stop layers are comprised of a same material as the passivation layer.

5. The structure of claim 1, wherein the MEMS device is positioned above the passivation layer to form a cavity above the sensing electrode, wherein a vertical distance between the sensing electrode and a lowermost surface of the MEMS substrate in the cavity is defined as a sensing gap.

6. The structure of claim 5, wherein the cavity is hermetically sealed.

7. The structure of claim 1, further comprising:

bonding electrodes arranged between the substrate and the MEMS substrate, wherein the bonding electrodes comprise a layer of a bonding structure.

8. The structure of claim 7, wherein the bonding electrodes are laterally spaced from the sensing electrode.

9. The structure of claim 7, wherein the bonding electrodes form cavity sidewalls of a cavity, and wherein the cavity is arranged around a sensing electrode.

10. The structure of claim 1, wherein the sensing electrode has angled sidewalls that cause a width of the sensing electrode to decrease as a distance from the substrate increases.

11-17. -17. (canceled)

18. A structure for a microelectromechanical systems (MEMS) device, the structure comprising:

an interlayer dielectric (ILD) region positioned over a substrate;

an inter-metal dielectric (IMD) region positioned over the ILD region, wherein the IMD region is comprised of a passivation layer overlying a stacked structure, wherein the stacked structure alternates between dielectric layers and etch stop layers, and wherein metal wire layers are disposed within the stacked structure of the IMD region; and

a sensing electrode electrically connected to the IMD region with an electrode extension via, wherein the sensing electrode is positioned adjacent a MEMS device such that a cavity is formed between the sensing electrode and the MEMS device; and

bonding electrodes comprising a layer of a bonding structure, wherein the bonding electrodes form cavity sidewalls of the cavity.

19. The structure of claim 18, wherein a sensing gap is arranged between a passivation surface of the sensing electrode and a lowermost surface of the MEMs device.

20. The structure of claim 18, wherein the electrode extension via comprises tungsten.

21. A structure, comprising:

an inter-metal dielectric (IMD) region arranged over a semiconductor substrate, wherein the IMD region comprises a silicon nitride passivation layer overlying a stacked structure, wherein the stacked structure alternates between dielectric layers and etch stop layers, wherein metal wire layers are disposed within the stacked structure of the IMD region, and wherein the silicon nitride passivation layer includes an opening exposing an upper metal wire layer of the IMD region;

a conductive material arranged within the opening to form one or more electrode extension vias;

an electrode layer having electrodes that have lower surfaces that directly contact the silicon nitride passivation layer, wherein the electrodes include sensing electrodes and bonding electrodes positioned over the one or more electrode extension vias, wherein the silicon nitride passivation layer continuously extends between a bottom surface contacting the upper metal wire layer and a top surface contacting the sensing electrodes and the bonding electrodes;

a MEMs substrate coupled to the bonding electrodes and having soft mechanical structures configured to move in a direction normal to upper surfaces of the sensing electrodes, wherein the soft mechanical is directly over and vertically separated from the sensing electrodes; and

a carrier substrate separated from the silicon nitride passivation layer by the MEMs substrate.

23. The structure of claim 21, wherein the silicon nitride passivation layer comprises a bottommost surface that directly contacts a topmost dielectric layer within the IMD region and the upper metal wire layer.

24. The structure of claim 21, wherein the sensing electrodes are electrically connected to the one or more electrode extension vias.

25. The structure of claim 21, wherein the carrier substrate comprises one or more cavities arranged directly over the sensing electrodes.

26. The structure of claim 21, wherein the metal wire layers comprise copper and the one or more electrode extension vias comprise tungsten.

27. The structure of claim 21, wherein the sensing electrode comprises titanium or tantalum.

28. The structure of claim 21, wherein the bonding electrodes form cavity sidewalls of a cavity, and wherein the cavity is arranged around a sensing electrode.

22. (canceled)