KR100296382B1 - Method for fabricating planar lightwave optical module - Google Patents

Abstract

The present invention relates to an optical module fabrication method capable of simultaneously performing optical and electrical processing functions on a single substrate by integrating an optoelectronic device in a planar waveguide optical circuit. The optical module fabrication method includes an optoelectronic device in a planar waveguide optical circuit. In the optical module manufacturing method that can integrate the device to perform the optical and electrical processing function on a single substrate at the same time, (a) the core layer of the core layer to integrate the optoelectronic device on the lower cladding layer and the core layer formed Etching a portion; (b) depositing an etch stop layer on the portion where the core layer is etched; (c) depositing an upper cladding layer over the etched core layer; (d) etching a portion of the upper cladding layer to an etch stop layer; And (e) attaching the optoelectronic device on the etch stop layer.

According to the present invention, the silicon substrate does not need to be etched in the form of a terrace, and the planarization step is also unnecessary. In addition, no deposition of the height adjustment film is required. Since the etch stop film is deposited on the lower cladding silica film, a separate insulating film is not required. As a result, the manufacturing time of the planar waveguide optical module is shortened and the cost is reduced.

Description

Method for fabricating planar lightwave optical module

The present invention relates to an optical module manufacturing method for integrating optoelectronic components in a planar waveguide optical circuit, and more particularly, to a planar waveguide optical module manufacturing method for integrating optoelectronic components in an etched planar waveguide optical circuit using an etch stop film. It is about.

Planar Lightwave Circuit (PLC) is applied to optical devices such as optical splitter or optical coupler. Recently, optical and electrical processing functions are simultaneously performed on a single substrate by integrating an optoelectronic device such as a laser or a photodetector or an optoelectronic integrated circuit (OEIC) such as an optical receiver. It is also applied in the form of an optical module. Such an optical module integrates optoelectronic devices on a PLC platform, and mainly uses hybrid integration technology such as flip-chip bonding.

Hybrid module technology of optical module is a technology that combines PLC platform and optoelectronic device with silica waveguide on silicon substrate and then solder using solder. At this time, the optoelectronic device uses a flip chip coupling method in which the surface on which the device is manufactured is attached to the silicon substrate. The silicon substrate is manufactured in the form of a terrace to help align the core of the silica waveguide when attaching the optoelectronic device, and a thin silica film is installed for insulation between the optoelectronic device and the substrate.

1A to 1J illustrate a manufacturing method of an optical module for integrating an optoelectronic component into a planar waveguide optical circuit according to the related art.

The silicon substrate 110 is first etched into a terrace (FIG. 1A), and then the silica bottom cladding layer 120 is deposited (FIG. 1B) and then planarized by a lapping process (FIG. 1C). Thereafter, a silica film 150 and a core layer 130 are deposited to adjust the height (FIG. 1D). Thereafter, the core layer 130 is etched to form an optical waveguide (FIG. 1E), and then the upper cladding layer 140 is deposited (FIG. 1F). Then, the silica film 150 of the platform portion to which the optoelectronic device is attached is removed (FIG. 1G), and the insulating silica film 160 is deposited (FIG. 1H). After depositing the solder 170 to produce a desired pattern (FIG. 1i), the optoelectronic device 180 is attached through a flip chip bonding process to complete the optical module.

This technique has a disadvantage in that the process process is complicated and takes a long time. First, the silica substrate 110 must be etched in a terrace form, and the core layer 130 and the lower cladding layer 120 are planarized between deposition processes. 1c). The height adjustment layer 150 is deposited below the core layer 130 to adjust the height of the core layer 130 and the terrace to an appropriate difference, so that the vertical portion of the output portion of the optoelectronic device 180 and the core layer 130 of the optical waveguide. Sorting is possible. In addition, the silica film 160 must be separately deposited for insulation between the silicon substrate 110 and the optoelectronic device 180. These processes make the silicon platform difficult and reduce production productivity.

The problem to be achieved by the present invention is to eliminate the process of etching the silicon substrate in the form of a terrace in the prior art using an etch-stop layer in the process to minimize the process processor and shorten the manufacturing time to improve productivity The present invention provides a method for manufacturing a waveguide optical module.

1A to 1J illustrate a manufacturing method of an optical module for integrating an optoelectronic component into a planar waveguide optical circuit according to the related art.

2A to 2G illustrate a manufacturing method of an optical module for integrating an optoelectronic component in a planar waveguide optical circuit according to the present invention.

In order to solve the above technical problem, the method for manufacturing a planar waveguide optical module according to the present invention integrates an optoelectronic device in a planar waveguide optical circuit and simultaneously performs optical and electrical processing functions on a single substrate. A method comprising: (a) etching a portion of a core layer to integrate the optoelectronic device on a substrate having a lower cladding layer and a core layer; (b) depositing an etch stop layer on the core layer; (c) depositing an upper cladding layer on the etched core layer; (d) etching a portion of the upper cladding layer to an etch stop layer; And (e) attaching the optoelectronic device on the etch stop layer.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2A to 2G illustrate a manufacturing process of the silica planar waveguide optical module according to the present invention. Unlike the prior art, the lower cladding layer 220 and the core layer 230 are deposited on a flat substrate 210 that is not manufactured in a terrace form (FIG. 2A). The lower cladding layer 220 and the core layer 230 are deposited by a silica film. Silica film deposition has many methods, including conventional flame hydrolysis deposition (FHD), atmospheric pressure chemical vapor deposition (APCVD), and plasma enhanced chemical vapor deposition (PECVD). Can be used.

The lower cladding layer 220 and the core layer 230 deposited on the substrate 210 are etched in a predetermined portion so that the output portion of the optoelectronic device is vertically aligned with the core layer 230 on the substrate 210 (FIG. 2b). The etch stop layer 250 is deposited on the etched lower cladding layer 220 to form a pattern (FIG. 2C). The etch stop layer 250 has a high etch selectivity with silica and is made of a material that is not oxidized or corroded when the upper cladding layer 240 is deposited. The etch stop layer 250 may use chromium (Cr), tungsten silicide (WSi), silicon, titanium (Ti), or the like.

The upper cladding layer 240 is deposited on the etched lower cladding layer 220 and the core layer 230 (FIG. 2D). The upper cladding layer 240 covering the portion where the optoelectronic device is assembled is removed to the etch stop layer 250 (FIG. 2E). Solder 260 is deposited on the etch stop film 250 (FIG. 2F). The optoelectronic device 270 is attached onto the solder 260 through a flip chip bonding process to complete the optical module manufacturing (FIG. 2G).

The optoelectronic device 270 may attach a laser diode LD, a photodetector, an optical modulator, an optical amplifier, or the like.

In the present invention, the passive alignment of the optoelectronic device 270 and the optical waveguide core layer 230 is implemented using the etch stop layer 250 instead of the conventional silicon terrace type. Since the thickness of the core layer 230 may be set during deposition, the position of the etch stop layer 250 may be accurately set by adjusting the depth of etching. When the upper cladding layer 240 is removed, the etch stops at the etch stop layer 250, so that vertical alignment with the core layer 230 of the optical waveguide is automatically performed when the optoelectronic device 270 is assembled. In addition, when the etch stop layer 250 is deposited, the alignment marks are horizontally aligned with the etched waveguide pattern, and when the etch stop layer 250 is manufactured, the alignment marks are horizontally aligned using the alignment marks when the optoelectronic device 270 is assembled.

According to the present invention, there is no need to etch the silicon substrate in the form of a terrace, and the planarization step is also unnecessary. In addition, no deposition of the height adjustment film is required. Since the etch stop film is deposited on the lower cladding silica film, a separate insulating film is not required. As a result, the manufacturing time of the planar waveguide optical module is shortened and the cost is reduced.

Claims (4)

In the optical module manufacturing method capable of simultaneously performing optical and electrical processing functions on a single substrate by integrating an optoelectronic device in a planar wave type optical circuit, (a) etching a predetermined portion of the core layer and the lower cladding layer on a flat substrate having a lower cladding layer and a core layer such that an output portion of the optoelectronic device is vertically aligned with the core layer; (b) depositing an etch stop layer on the etched predetermined portion of the lower cladding layer; (c) depositing an upper cladding layer on the etched core layer; (d) etching a portion of the upper cladding layer to an etch stop layer; And (e) attaching the optoelectronic device on the etch stop layer. The method of claim 1, wherein step (b) And depositing the etch stop layer on the etched predetermined portion of the lower cladding layer with a material having a high etching selectivity with silica and not being oxidized or corroded when the upper cladding layer is deposited. The method of claim 2, wherein the etch stop layer is Method of manufacturing a planar waveguide optical module, characterized in that made of silicon, chromium (Cr), tungsten silicide (WSi) or titanium (Ti). The method of claim 1, wherein step (e) And depositing solder on the etch stop layer and attaching the optoelectronic device to the solder through flip chip bonding.