Bulk acoustic wave resonator with an integrated passive device fabricated using bump process
A circuit includes a semiconductor substrate and an integrated passive device. The integrated passive device is on a surface of the semiconductor substrate. The integrated passive device is in a metal layer on the semiconductor substrate. The metal layer is at least tens of micrometers thick. The integrated passive device may be an inductor or a capacitor in some examples.
1 . A circuit, comprising:
a semiconductor substrate;
an inductor over the semiconductor substrate;
a resonator on the semiconductor substrate, the resonator coupled in series with the inductor; and
a seal ring over the semiconductor substrate and at least partially surrounding the inductor, the seal ring and the inductor made of a same material.
2 . The circuit of claim 1 , wherein the resonator is a first resonator, and the circuit includes a second resonator coupled to the first resonator.
3 . The circuit of claim 2 , wherein the inductor is coupled between the first and second resonators.
4 . The circuit of claim 1 , wherein the inductor and the seal ring have a same thickness.
5 . The circuit of claim 1 , further comprising a second substrate coupled to the seal ring via solder.
6 . The circuit of claim 1 , further comprising:
a first I/O terminal over the semiconductor substrate; and
a second I/O terminal over the semiconductor substrate;
wherein:
the inductor includes:
a first terminal coupled to the first I/O terminal; and
a second terminal; and
the resonator includes:
a first terminal coupled to the second terminal of the inductor; and
a second terminal coupled to the second I/O terminal.
7 . The circuit of claim 1 , wherein the seal ring includes a copper post or a copper bump.
8 . The circuit of claim 1 , further comprising:
a first I/O terminal over the semiconductor substrate; and
a second I/O terminal over the semiconductor substrate; and
wherein:
the inductor includes:
a first terminal coupled to the first I/O terminal; and
a second terminal coupled to the second I/O terminal.
9 . The circuit of claim 1 , further comprising:
a first I/O terminal over the semiconductor substrate;
a second I/O terminal over the semiconductor substrate; and
a capacitor over the semiconductor substrate; and
wherein:
the inductor includes:
a first terminal coupled to the first I/O terminal; and
a second terminal coupled to the second I/O terminal and a terminal of the capacitor.
10 . The circuit of claim 9 , wherein:
the inductor is a first inductor; and
the circuit includes:
a second inductor over the semiconductor substrate; and
the second inductor includes:
a first terminal coupled to the first terminal of the first inductor; and
a second terminal coupled to the second I/O terminal.
11 . The circuit of claim 1 , wherein the resonator is a micro-electro-mechanical system (MEMS) resonator.
12 . The circuit of claim 11 , wherein the MEMS resonator is a bulk acoustic wave (BAW) resonator.
13 . The circuit of claim 1 , wherein the inductor is at least 30 micrometers thick.
14 . A circuit, comprising:
a semiconductor substrate;
a resonator over the semiconductor substrate;
an inductor over the semiconductor substrate, in which the inductor is coupled in series to the resonator; and
a seal ring over the semiconductor substrate, in which the seal ring at least partially laterally surrounds the inductor and the resonator.
15 . The circuit of claim 14 , further comprising a base die coupled to the seal ring, wherein the base die is spaced from the inductor.
16 . The circuit of claim 14 , further comprising:
a first I/O terminal over the semiconductor substrate; and
a second I/O terminal over the semiconductor substrate; and
wherein:
the inductor includes:
a first terminal coupled to the first I/O terminal; and
a second terminal coupled to the second I/O terminal.
17 . The circuit of claim 14 , further comprising:
a first I/O terminal over the semiconductor substrate; and
a second I/O terminal over the semiconductor substrate;
wherein:
the inductor includes:
a first terminal coupled to the first I/O terminal; and
a second terminal;
the resonator includes:
a first terminal coupled to the second terminal of the inductor; and
a second terminal coupled to the second I/O terminal.
18 . A circuit, comprising:
a first die including a semiconductor substrate;
a first I/O terminal over the semiconductor substrate;
a second I/O terminal over the semiconductor substrate;
a passive device over the semiconductor substrate and includes a terminal coupled to the first I/O terminal;
a seal ring that surrounds the passive device, the first I/O terminal, and the second I/O terminal, the seal ring having a same material as the passive device and the first and second I/O terminals; and
a second die coupled to first I/O terminal and to the second I/O terminal, in which at least part of the passive device is spaced from at least one of the first or second dies.
19 . The circuit of claim 18 , wherein the terminal of the passive device is a first terminal, the circuit further comprising:
a capacitor over the semiconductor substrate, and the capacitor includes a terminal coupled to the terminal of the passive device; and
wherein the passive device includes a second terminal coupled to the second I/O terminal.
20 . The circuit of claim 19 , wherein the passive device is a first inductor, the circuit further comprising a second inductor over the semiconductor substrate and wherein the second inductor includes:
a first terminal coupled to the first terminal of the first inductor; and
a second terminal coupled to the second I/O terminal.