CN103852821A

CN103852821A - Silicon through hole manufacturing method for optical fiber alignment base

Info

Publication number: CN103852821A
Application number: CN201210510461.4A
Authority: CN
Inventors: 吴智勇; 刘鹏; 袁苑
Original assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2012-12-03
Filing date: 2012-12-03
Publication date: 2014-06-11

Abstract

The invention discloses a silicon through hole manufacturing method for an optical fiber alignment base. The silicon through hole manufacturing method comprises the steps of (1) depositing a silicon dioxide etching stopping layer on the back face of a silicon substrate, (2) depositing a silicon dioxide hard mask on the front face of the silicon substrate, (3) etching and defining a graph of a silicon through hole through photoetching and the silicon dioxide hard mask dry method, (4) forming the inverted funnel type silicon through hole through the high selection ratio anisotropism drying etching technology, (5) removing polymers formed in the above etching steps, and (6) conducting wet etching to remove the silicon dioxide mask. According to the silicon through hole manufacturing method for the optical fiber alignment base, the silicon substrate is etched through the high selection ratio anisotropism drying etching technology, a bell mouth circular hole formed in the back face of the silicon substrate is used as an optical fiber alignment base array, the number of technological processes is effectively reduced, the cost is reduced, and the yield is improved.

Description

For the silicon perforation method for making of optical fiber align pedestal

Technical field

The present invention relates to SIC (semiconductor integrated circuit) and manufacture field, particularly relate to a kind of perforation of the silicon for optical fiber align pedestal (OFA) method for making.

Background technology

Current, the application of optical communication device is more and more extensive, and engineering that Fiber to the home also starts progressively to carry out in national the greater part.In a photosystem, need the processing of multiple optical-fibre channels for light signal, meet system requirements and elongated optical fiber need to be fixed on the quality of guarantee fixed fiber on the optical fiber align pedestal of One's name is legion.Therefore, optical fiber align pedestal needs alignment precision requirement high and process stabilizing could meet light signal efficiency by loss not too much.The optical fiber through hole pedestal that at present method of the conventional lf glass of industry is made, because manufacture craft is coarse, alignment precision is low, the shortcoming of the high and inefficiency of cost, in the urgent need to a kind of high precision, the manufacture craft of low cost and high yield replaces it.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of perforation of the silicon for optical fiber align pedestal method for making, and it can reduce technological process effectively, cost-saving.

For solving the problems of the technologies described above, the perforation of the silicon for optical fiber align pedestal method for making of the present invention, step comprises:

1) at silicon substrate back side deposit layer of silicon dioxide etching stop layer;

2) at the hard mask of the positive deposit layer of silicon dioxide of silicon substrate;

3) by size and the surfacial pattern of photoetching and the perforation of the hard mask dry etching definition of silicon dioxide silicon;

4) form the silicon of falling funnel type perforation by high selectivity anisotropic dry etch process;

5) remove the polymkeric substance forming in above each etch step;

6) wet etching is removed silicon dioxide film.

The present invention is carved and is worn silicon substrate by the dry etch process of high selectivity, form hydraucone circular hole at the silicon substrate back side as optical fiber align pedestal array, hydraucone is as the front of optical fiber insert port, and this technique has not only effectively reduced technological process, save cost, and improved yield.

Accompanying drawing explanation

Fig. 1 is the top figure of the silicon perforation of the embodiment of the present invention.

Fig. 2 is the bottom figure of the silicon perforation of the embodiment of the present invention.

Fig. 3 is the fabrication processing schematic diagram of the silicon perforation of the embodiment of the present invention.

In figure, description of reference numerals is as follows:

1: monocrystalline silicon substrate

2: silicon dioxide

3: photoresist

4: the perforation of bottom chamfer silicon

Embodiment

Understand for technology contents of the present invention, feature and effect being had more specifically, existing in conjunction with illustrated embodiment, details are as follows:

Silicon for the optical fiber align pedestal perforation of the present embodiment, its concrete fabrication processing is as follows:

Step 1, passes into the mixed gas of silane and oxygen, with chemical gas-phase deposition method in silicon substrate back side deposit layer of silicon dioxide (thickness >=2.5 micron) as etching stop layer, as shown in Fig. 3 (a), to prevent etching gas damage etch equipment suction tray.Deposition conditions is: normal pressure, temperature is 350～450 degrees Celsius.

Step 2, passes into the mixed gas of silane and oxygen, with chemical gas-phase deposition method at the positive hard mask of deposit layer of silicon dioxide of silicon substrate (thickness >=4.5 micron), as shown in Figure 3 (b).Deposition conditions is: normal pressure, temperature is 350～450 degrees Celsius.

Step 3, coating photoresist, by photoetching (as shown in Figure 3 (c)) and the hard mask dry etching of silicon dioxide (as shown in Fig. 3 (d)), defines size and the surfacial pattern of silicon perforation get off.The diameter of silicon perforation is between 120～150 microns, than the slightly larger in diameter of optical fiber.

Step 4, by high selectivity anisotropic dry etch process, forms the silicon of falling funnel type perforation, as shown in Fig. 3 (e).

This high selectivity anisotropic dry etch process comprises deposit (deposit is containing the organic polymer thin film of the elements such as C, F), high strength etching and three steps of low-intensity etching, these three steps occur in the circulation of etching process high frequency, to reach the high etch rate of monocrystalline silicon (>=10 μ m/min), the effect of monocrystalline silicon to the high etching selection ratio of silicon dioxide (>=250), the silicon substrate of 725 μ m left and right is carved and worn, form the silicon passage that fixed fiber is used.This silicon passage has straight profile, and whole silicon passage keeps same size from top to down.

After silicon substrate is carved and is worn, utilize the high etching selection ratio of monocrystalline silicon to silicon dioxide, strengthen over etching amount, because plasma cannot be at longitudinal etching silicon dioxide, plasma meeting transverse dispersion, forms larger lateral openings in silicon substrate bottom, and this larger lateral openings just makes silicon perforated bottom profile form chamfering (150～180 microns of a maximum lateral width, the degree of depth is 20～30 microns), as shown in Fig. 3 (e), optical fiber just can insert smoothly from this chamfering.

The process conditions of above-mentioned three steps are as follows:

Deposition conditions is: pressure 40～50 person of outstanding talent's holders, and 1000～1200 watts of upper electrode power, lower electrode power is the progressive formation of 10 watts to 20 watts, gas is C ₄f ₈, single step deposition time is the progressive formation of 1.5 seconds to 2.5 seconds.

High strength etching condition is: pressure 40～50 person of outstanding talent's holders, and 1000～1200 watts of upper electrode power, lower electrode power is the progressive formation of 70 watts to 100 watts, gas is SF ₆, single step etching time is the progressive formation of 1.5 seconds to 2.5 seconds.

Low-intensity etching condition is: pressure 40～50 person of outstanding talent's holders, and 1000～1200 watts of upper electrode power, the progressive formation that lower electrode power is 30 watts to 50 watts, gas is SF ₆, single step etching time is the progressive formation of 2.5 seconds to 3.5 seconds.

Step 5, is used oxygen that the polymkeric substance forming in above etch step is removed clean, and this process using pressure is 6～10 holders, and upper electrode power is 1000～2000 watts.

Step 6, wet etching, removes silica dioxide medium film, as shown in Fig. 3 (f).Can working concentration the hydrofluorite that is 49% the silicon dioxide restraining barrier at the back side and the positive hard mask residual fraction of silicon dioxide are removed clean, also can use ammonium fluoride solvent that silicon dioxide is dissolved.

Finally, silicon substrate is turned out, bottom-up, face down, the perforation of the especially big silicon of this infundibulate just can be for optical fiber align pedestal like this.

Claims

1. for the silicon perforation method for making of optical fiber align pedestal, it is characterized in that, step comprises:

3) by the figure of photoetching and the perforation of the hard mask dry etching definition of silicon dioxide silicon;

5) remove the polymkeric substance forming in above each etch step;

6) wet etching is removed silicon dioxide film.

2. method according to claim 1, is characterized in that, step 1) and 2), adopt chemical gas-phase deposition method, deposition conditions is: normal pressure, 350～450 degrees Celsius of temperature, gas is the mixed gas of silane and oxygen.

3. method according to claim 1, is characterized in that, the thickness of described silicon dioxide etching stop layer is more than 2.5 microns; The thickness of the hard mask of described silicon dioxide is more than 4.5 microns.

4. method according to claim 1, is characterized in that, step 4), and described high selectivity anisotropic dry etch process comprises deposit, high strength etching and three steps of low-intensity etching, and these three step high-frequencies loop.

5. method according to claim 4, it is characterized in that, the process conditions of the depositing step in described high selectivity anisotropic dry etch process are: pressure 40～50 person of outstanding talent's holders, 1000～1200 watts of upper electrode power, lower electrode power is the progressive formation of 10 watts to 20 watts, and gas is C ₄f ₈, single step deposition time is the progressive formation of 1.5 seconds to 2.5 seconds.

6. method according to claim 4, is characterized in that, the process conditions of described high strength etch step are: pressure 40～50 person of outstanding talent's holders, and 1000～1200 watts of upper electrode power, lower electrode power is the progressive formation of 70 watts to 100 watts, gas is SF ₆, single step etching time is the progressive formation of 1.5 seconds to 2.5 seconds.

7. method according to claim 4, is characterized in that, the process conditions of described low-intensity etch step are: pressure 40～50 person of outstanding talent's holders, and 1000～1200 watts of upper electrode power, the progressive formation that lower electrode power is 30 watts to 50 watts, gas is SF ₆, single step etching time is the progressive formation of 2.5 seconds to 3.5 seconds.

8. according to the method described in claim 1 or 4, it is characterized in that, step 4), monocrystalline silicon etch rate more than 10 μ m/min, monocrystalline silicon to the etching selection ratio of silicon dioxide more than 250.

9. method according to claim 1, is characterized in that, the diameter of described silicon perforation is 120～150 microns, 150～180 microns of the maximum lateral width of silicon perforated bottom chamfering, and the degree of depth is 20～30 microns.

10. method according to claim 1, is characterized in that, step 5) is used oxygen, and pressure is 6～10 holders, and upper electrode power is 1000～2000 watts.