Germanium/silicon mixedly intgegrated wave guide type photoelectric converter and its manufacture method

Abstract

The invention relates to the technical field of photoelectric converters, and discloses a Ge / Si combined integrated waveguide photoelectric converter. The Ge / Si combination integrated waveguide photoelectric converter is made by welding an Si-based SOI waveguide (3) to an inverse Ge-based transverse p-i-n structure, wherein, the Ge-based transverse p-i-n structure is composed of a waveguide intrinsic region (4), and p and n doping regions (7 and 8) arranged on two sides of the waveguide; and light signals are input by the Si waveguide (3), and then coupled into the Ge waveguide (4) through an evanescent field, and the light signals undergo photoelectric conversion in the Ge p-i-n structure. Meanwhile, the invention discloses a method for manufacturing the Ge / Si combination integrated waveguide photoelectric converter. The invention can be utilized for integrating a photoelectric converting device with a micro-electronic chip, and meanwhile, enhancing the responsivity, the frequency response and the sensitivity of the photoelectric converter.

Description

technical field [0001] The invention relates to the technical field of photoelectric converters, in particular to a 1.55-band germanium-silicon Ge / Si mixed-integrated waveguide photoelectric converter compatible with CMOS technology and a manufacturing method thereof. Background technique [0002] With the development of high-density and large-capacity data transmission and computing, the advantages of integrating optoelectronics and microelectronics on a chip are becoming more and more obvious, and the demand is becoming more and more urgent. It is of great importance to the development of our national economy, national security and scientific progress play an important supporting role. For this reason, a large number of optical passive devices have been developed on Si-based SOI waveguides by using the mature Si process and the transparency of Si in the communication band. However, the research progress on Si-based optical active devices is slow. The reason is not only th...

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Problems solved by technology

However, the lattice mismatch between Ge and Si is as high as 4%, and there are certain difficulties in direct growth; secondly, the usual discrete devices are used to detect optical signals perpendicular to the surface of the film, and cannot be integrated with planar optical waveguides; thirdly, in discrete devices Light absorption requires intrinsic layer thickness and carrier drift requires intrinsic layer thickness to be contradictory; fourth, the process used in discrete devices is not compatible with complementary metal-oxide-semiconductor (CMOS) processes, and thus cannot be integrated with microelectronics

In response to these deficiencies, many researchers have developed lateral devices connected to waveguides, which can be divided into two categories: one is the pn or p-i-n structure stacked up and down by epitaxial growth in the early stage (H.Temkin, et.al .,"Ge x Si 1-x trained-layersuperlattice waveguide photo-detectors operating near 1.3μm”, AppliedPhysics Letters, 48:963-65, 1986), its advantage is that it can copy the growth of various materials in discrete devices to meet the needs of lateral devices, the disadvantage is that it is compatible with CMOS The metal electrode on the top absorbs the optical signal strongly and causes loss; the other type is the recently developed lateral p-i-n structure, which uses ion implantation to form divacancy complex defects in Si, and the valence band Electrons jump to deep energy levels (defect light absorption) after absorbing photons (E.V.Monakhov, et.al., "Divacancy annealing in Si: Influence of hydrogen", Physical Review B, 69:153202, 2006), and release after saturation Electronics, whose biggest advantage is compatibility with CMOS and integration with optoelectronics, although the efficiency of defect light absorption is low, it can be compensated by extending the absorption waveguide

First of all, the light absorption rate is low, and the light absorption rate of defects is often several orders of magnitude lower than the interband absorption; secondly, the electron transport mechanism is unknown. In principle, the Si waveguide absorption is due to the Si + The double-vacancy compound defect caused by ion implantation belongs to the deep energy level, and the valence band electrons absorb photons and jump to the deep energy level of the defect, but it is not clear how the electrons are transported from the deep energy level to the electrode. From the previous It can be seen from the literature that when the waveguide cross-section is 5×5μm 2 , its responsivity is very low, which makes the device preparation blind

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