Method and system for a low parasitic silicon high-speed phase modulator using PN finger waveguides
Methods and systems for a low-parasitic silicon high-speed phase modulator are disclosed and may include in an optical phase modulator that comprises a PN junction waveguide formed in a silicon layer, wherein the silicon layer may be on an oxide layer and the oxide layer may be on a silicon substrate. The PN junction waveguide may have fingers of p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide. Contacts may be formed on the fingers of p-doped and n-doped regions. The fingers of p-doped and n-doped regions may be arranged symmetrically about the PN junction waveguide or staggered along the length of the PN junction waveguide. Etch transition features may be removed along the p-doped and n-doped regions.
1. A method for a semiconductor device, the method comprising:
in an optical phase modulator that comprises:
a PN junction waveguide formed in a silicon layer, said PN junction waveguide having p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide with only p-doping on a first of said opposite sides and only n-doping on a second of said opposite sides; and
raised fingers of p-doped and n-doped regions along said PN junction waveguide, wherein a major axis of said raised fingers is perpendicular to said PN junction waveguide and a minor axis of said raised fingers is parallel to said PN junction waveguide:
receiving an input optical signal; and
applying a voltage to said raised fingers to modulate said received input optical signal.
2. The method according to claim 1 , wherein the raised fingers of p-doped and n-doped regions are arranged symmetrically about the PN junction waveguide.
3. The method according to claim 1 , wherein the raised fingers of p-doped and n-doped regions are arranged in a staggered fashion along the length of the PN junction waveguide.
4. The method according to claim 1 , comprising communicating the modulated optical signal into an optical fiber.
5. The method according to claim 1 , wherein the silicon layer is in a silicon-on-insulator (SOI) complementary metal-oxide semiconductor (CMOS) wafer.
6. The method according to claim 1 , comprising receiving the input optical signal from a laser source bonded to the silicon layer.
7. The method according to claim 1 , wherein the optical phase modulator is integrated in an optical transceiver formed on a silicon substrate.
8. The method according to claim 1 , wherein the raised fingers comprise contacts that are staggered on opposite sides along the length of the PN junction waveguide.
9. The method according to claim 1 , wherein the raised fingers of p-doped and n-doped regions extend up from an oxide layer under the silicon layer on a silicon substrate.
10. The method according to claim 1 , wherein the optical phase modulator is integrated in a Mach-Zehnder interferometer modulator.
11. A system for communication, the system comprising:
an optical phase modulator that comprises:
a PN junction waveguide formed in a silicon layer;
first p-doped and n-doped regions on opposite sides along a length forming the PN junction waveguide with only p-doping on a first of said opposite sides and only n-doping on a second of said opposite sides; and
raised fingers of p-doped and n-doped regions along said PN junction waveguide, wherein a major axis of said raised fingers is perpendicular to said PN junction waveguide and a minor axis of said raised fingers is parallel to said PN junction waveguide, said optical phase modulator being operable to:
receive an input optical signal; and
apply a voltage to said raised fingers to modulate said received input optical signal.
12. The system according to claim 11 , wherein the raised fingers of p-doped and n-doped regions are arranged symmetrically about the PN junction waveguide.
13. The system according to claim 11 , wherein the raised fingers of p-doped and n-doped regions are arranged in a staggered fashion along the length of the PN junction waveguide.
14. The system according to claim 11 , wherein the modulated optical signal is communicated into an optical fiber.
15. The system according to claim 14 , wherein the raised fingers of p-doped and n-doped regions comprise contacts staggered on opposite sides along the length of the PN junction waveguide.
16. The system according to claim 11 , wherein the silicon layer is in a silicon-on-insulator (SOI) complementary metal-oxide semiconductor (CMOS) wafer.
17. The system according to claim 11 , wherein the optical phase modulator is integrated in an optical transceiver formed on a silicon substrate.
18. The system according to claim 11 , wherein the raised fingers of p-doped and n-doped regions extend up from an oxide layer under the silicon layer on a silicon substrate.
19. The system according to claim 11 , wherein the optical phase modulator is integrated in a Mach-Zehnder interferometer modulator.
20. A system for communication, the system comprising:
a Mach-Zehnder optical modulator that comprises:
a PN junction waveguide formed in a silicon layer on an oxide layer in a silicon-on-insulator (SOI) complementary metal-oxide semiconductor (CMOS) substrate;
p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide with only p-doping on a first of said opposite sides and only n-doping on a second of said opposite sides; and
raised fingers of p-doped and n-doped regions along said PN junction waveguide, wherein a major axis of said raised fingers is perpendicular to said PN junction waveguide and a minor axis of said raised fingers is parallel to said PN junction waveguide, said Mach-Zehnder optical modulator being operable to:
receive an input optical signal; and
apply a voltage to said raised fingers to modulate said received input optical signal.