JPH0588036A - Waveguide film consisting of glass derived from siloxane polymer - Google Patents

Abstract

PURPOSE:To obtain the waveguide film which is low in loss from a visible light to near IR region, allows the easy control of refractive indices and has excellent heat resistance by forming the waveguide film having two kinds of specific repeating units. CONSTITUTION:This waveguide film consists of the glass derived from the siloxane polymer having the repeating unit expressed by formula I and the repeating unit expressed by formula II. In the formula I, R1 denotes the alkyl group expressed by CnY2n+1 (Y is hydrogen, deuterium or halogen; n is positive integer <=5), deuterated or halogenated alkyl group or the phenyl group expressed by C6Y5 (Y is hydrogen, deuterium or halogen), deuterated or halogenated phenyl group. In the formula II, M1 is quadriment elements exclusive of Si; R2 is the alkyl group expressed by CnY2n+1, deuterated or halogenated alkyl group or the phenyl group expressed by C6Y5, deuterated or halogenated alkyl group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide film made of glass derived from a siloxane polymer, which can be used as a waveguide for optical integrated circuits.

[0002]

2. Description of the Related Art As a base material for optical parts and optical fibers, an inorganic material such as quartz glass or multi-component glass is generally used because of its small optical transmission loss and wide transmission band. On the other hand, plastic-based optical materials have also been developed. These plastic optical materials are attracting attention because they have characteristics such as better workability than inorganic materials and easy handling. For example, in an optical fiber, a concentric core in which a plastic having a high transparency such as polymethylmethacrylate (PMMA) or polystyrene is used as a core, and a plastic having a refractive index lower than that of the core is used as a sheath (clad) component. -Clad structures are known. However, these plastic optical fibers have a drawback in that the degree of attenuation of light transmitted inside is large as compared with inorganic fibers. Transmission of light is generally carried out by internally reflecting the incident light of an optical circuit or fiber along the length direction internally, but when the light is transmitted inside the plastic, the light is absorbed or scattered and It is important to minimize the factors that increase the damping. In optical circuit parts, the wavelength of light used in the current optical fiber communication is 650 nm to
Since the light of 1600 nm is used, when plastic is used, the loss reduction in that region is more urgent. As a method of solving this, it is possible to use a plastic material as a precursor and convert it into glass. For example, a silicon-based polymer is treated with oxygen plasma (A.
D. Buterus et al., Journal of Vacuum Science and Technology, Vol. 29, No. 17,
(Page 1197) or heating in air or oxygen (BG Bagley et al., Better Ceramics Through Chemistry p287) to convert it into glass. Onose et al. Have reported a new glass pattern formation method in which a silicon-based resist is patterned and then vitrified by heating (Onose,
Kimura, Journal of Photopolymer Science and Technology, Vol. 4, No. 1, p. 119). However, these only convert to the form of SiO ₂ and do not mention about refractive index control. Generally, the mode of propagating light changes depending on the refractive index ratio between the core and the clad, so that the refractive index control of each is important in determining the waveguide structure. Particularly, in the waveguide of the optical circuit component using the single mode, more precise and simple refractive index control is required.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to achieve low loss in the visible light to near-infrared light region, easily control the refractive index, and An object of the present invention is to provide a waveguide film made of glass derived from a siloxane-based polymer having excellent heat resistance.

[0004]

In order to solve such a problem, a waveguide film made of glass derived from a siloxane-based polymer of the present invention has the following general formula (I):

[0005]

[Chemical 7]

[Wherein R ₁ is an alkyl group represented by C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, and n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, Or a repeating unit represented by C ₆ Y ₅ (Y is hydrogen, deuterated or halogen), a deuterium or halogenated phenyl group] and the following general formula (II):

[0007]

[Chemical 8]

[Wherein M ₁ is a tetravalent element excluding Si, R ₂
Is C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, n
Is a positive integer of 5 or less), an alkyl group represented by deuterated or halogenated alkyl group, or C ₆ Y ₅ (Y
Has a phenyl group represented by hydrogen, deuterium or halogen, and a repeating unit represented by a deuterated or halogenated phenyl group].

The waveguide film made of glass derived from the siloxane polymer of the present invention has the following general formula (III):

[0010]

[Chemical 9]

[Wherein R ₁ and R ₂ are the same or different, and C
_n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, n is 5
An alkyl group represented by the following positive integer), a deuterated or halogenated alkyl group, or a phenyl group represented by C ₆ Y ₅ (Y is hydrogen, deuterium or halogen),
A deuterated or halogenated phenyl group] and the following general formula (IV):

[0012]

[Chemical 10]

[Wherein M ₁ is a tetravalent element except Si, R
₃ , R ₄ are the same or different, and C _n Y _{2n + 1} (Y is hydrogen,
Deuterium or halogen, n is a positive integer of 5 or less), an alkyl group represented by deuterated or halogenated alkyl group, or phenyl represented by C ₆ Y ₅ (Y is hydrogen, deuterium or halogen) Group, a deuterated or halogenated phenyl group].

Furthermore, the waveguide film made of glass derived from the siloxane polymer of the present invention has the following general formula (I):

[0015]

[Chemical 11]

[Wherein R ₁ is an alkyl group represented by C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, Or a repeating unit represented by C ₆ Y ₅ (Y is hydrogen, deuterium or halogen), a deuterated or halogenated phenyl group] and the following general formula (V):

[0017]

[Chemical formula 12]

[Wherein M ₂ is a trivalent element excluding rare earths].

[0019]

The optical waveguide in the present invention is a glass derived from a siloxane polymer containing a trivalent or tetravalent element other than Si, that is, a combination of repeating units represented by the general formulas (I) and (II), A polymer having a combination of repeating units represented by (III) and (IV) or a combination of repeating units represented by the general formulas (I) and (V) is vitrified by thermal oxidation or treatment with oxygen plasma. The essence is to use the obtained glass. Examples of trivalent elements other than Si include Al, P, B and Bi. Also,
Examples of the tetravalent element include Ge, Sn, and Ti. By combining these repeating units or by copolymerization, those having various refractive indexes can be obtained, and the refractive index can be easily controlled.

The siloxane-based polymer used to make the glass used in the present invention is generally prepared as follows. That is, the following general formulas (VI), (VII),
(VIII)

[0021]

[Chemical 13]

[0022]

[Chemical 14]

[0023]

[Chemical 15]

[Wherein M is a tetravalent element, M'is a trivalent element excluding rare earths, R and R'are the same or different, and C _n Y
_{2n + 1} (Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, or C ₆ Y ₅ (Y is hydrogen,
A phenyl group represented by deuterium or halogen) and a chloride represented by deuterated or halogenated phenyl group] can be obtained by hydrolysis and polymerization. Also (V
The siloxane-based polymer can also be obtained by polymerization of various alcoholates obtained by reacting chlorides represented by I), (VII), and (VIII) with alcohols, and condensation polymerization of chlorides and alcoholates. When n is 6 or more, the glass transition temperature of the polymer is low, which causes a problem in handling, and n is preferably 5 or less.

Specific compounds of the chlorides represented by the formulas (VI), (VII) and (VIII) are, for example, phenyltrichlorosilane and phenyltrichlorosilane d-.
5, diphenyldichlorosilane, phenyltriethoxysilane, benzyltrichlorosilane, tetrakis (trimethylsiloxy) titanium, aluminum chloride, phosphorus chloride, boron chloride, bismuth chloride, phenyltin chloride, phenyltrichlorogermanium, diphenyldichlorogermanium, etc. Can be mentioned.

The method for producing the siloxane-based polymer used in the present invention is the same as the general method for producing polysiloxane, in which hydrolysis of chloride, alcoholate, etc. is dissolved in an organic solvent such as toluene, xylene, etc. The polymerization is carried out with an alkali. Further, the molecular weight of the siloxane-based polymer is preferably 100,000 or more in order to avoid cracking when a film is formed.

As a method for forming a film in the present invention, first, a polymer is dissolved in an appropriate solvent and then applied onto a substrate by a spin coating method, a dipping method or a spraying method so as to have a desired thickness. After baking to remove the solvent, it is heat-treated in an electric furnace at 500 to 1100 ° C. in the presence of oxygen or is treated with a cylindrical oxygen plasma etching apparatus to be vitrified.

Hereinafter, a siloxane-based polymer (hereinafter, referred to as a raw material of glass used for producing the waveguide film of the present invention)
An example of the production of a polymer) will be shown.

(Polymer Production Example 1) Content In a flask of about 100 ml, 100 g of KOH was added to 10 g of phenyltrichlorosilane and 1.3 g of aluminum chloride, and 15 m
Mix with 1 l of toluene. Then, this mixed liquid was refluxed for 16 hours. After completion of the reaction, the mixture was cooled, a small amount of precipitate was filtered, and then the solution was poured into methanol for reprecipitation. The obtained polymer is a siloxane polymer having a structure of R ₁ = phenyl group in the general formula (I) and a structure of M ₂ = Al in the general formula (V), IR analysis and NM
It was confirmed by R analysis. The molecular weight of the polymer is Mw =
It was 125000 and Mw / Mn = 6.1. The refractive index of this polymer was 1.60, which was 2.6% higher than that of Al-free polysilsesquioxane which was 1.56. Further, this polymer showed high heat resistance, and no change was observed even after heat treatment at 300 ° C. for 1 hour.

(Polymer Production Example 2) A deuterated polymer was obtained in the same manner as in Polymer Production Example 1 except that deuterated phenyltrichlorosilane d-5 was used as a raw material monomer. According to IR analysis and NMR analysis, the obtained polymer is a siloxane polymer having a structure of R ₁ = deuterated phenyl group in the general formula (I) and a structure of M ₂ = Al in the general formula (V). It could be confirmed. The physical properties of the obtained polymer were almost the same as those of the polymer of Polymer Production Example 1.

(Polymer Production Example 3) Contents In a flask of about 100 ml, 10 g of phenyltrichlorosilane and 2.4 g of phenyltrichlorogermanium were added with 100 mg of KOH and mixed with 15 ml of toluene. Then, this mixed liquid was refluxed for 16 hours. After completion of the reaction, the mixture was cooled, a small amount of precipitate was filtered, and then the solution was poured into methanol for reprecipitation. The obtained polymer has the structure of R ₁ = phenyl group in the general formula (I) and M in the general formula (II).
It was confirmed by IR analysis and NMR analysis that it was a siloxane-based polymer having a structure of ₁ = Ge, R ₂ = phenyl group. The molecular weight of the obtained polymer is Mw = 1360.
00 and Mw / Mn = 4.2. The refractive index of this polymer was 1.58, which was 1.2% higher than the Ge-free polysilsesquioxane of 1.56. Further, this polymer showed high heat resistance, and no change was observed even after heat treatment at 300 ° C. for 1 hour.

(Polymer Production Example 4) Contents Into a flask of about 100 ml, 100 g of KOH was added to 10 g of phenyltrichlorosilane and 1.3 g of phosphorus chloride and mixed with 15 ml of toluene. Then, this mixed liquid was refluxed for 18 hours. After completion of the reaction, the mixture was cooled, and after filtering a small amount of precipitate,
Reprecipitation was performed by pouring the solution into methanol. It was confirmed by IR analysis and NMR analysis that the obtained polymer was a siloxane polymer having a structure of R ₁ = phenyl group in the general formula (I) and a structure of M ₂ = P in the general formula (V). .. The molecular weight of the obtained polymer is Mw = 1.
It was 05000 and Mw / Mn = 4.5. The refractive index of this polymer was 1.57, which was 0.46 higher than that of Al-free polysilsesquioxane which was 1.56.

Polymer Production Examples 5, 6, 7, and 8 Polymers were synthesized by using the chlorides shown in Table 1 instead of phosphorus chloride in Polymer Production Example 4. The polymer obtained in Polymer Production Example 5 is a siloxane-based polymer having a structure of R ₁ phenyl group in the general formula (I) and a structure of M ₂ = B in the general formula (V), Polymer Production Example 6 The polymer obtained in (1) has the structure of R ₁ = phenyl group in the general formula (I) and M in the general formula (V).
_The polymer obtained in Polymer Production Example 7 is a siloxane-based polymer having a structure of ₂ = Bi.
Where R ₁ = phenyl structure and M ₁ = S in the general formula (II)
The polymer obtained in Polymer Production Example 8 is a siloxane-based polymer having a structure of n, R ₂ = phenyl group, and the polymer obtained in General Formula (I) has the structure of R ₁ = phenyl group and the general formula (II).
Are IR analysis and N, which are siloxane-based polymers having a structure of M ₁ = Ti, R ₂ = phenyl group.
It was confirmed by MR analysis. Table 1 shows the molecular weight and refractive index of the obtained polymer.

[0034]

[Table 1]

(Polymer Production Example 9) 5 g of phenyltrichlorosilane d-5 and pentyltrichlorosilane d-11
4.5g to 100g aluminum chloride to 1.3g K
OH was added and mixed with 15 ml toluene. Then, this mixed liquid was refluxed for 24 hours. After completion of the reaction, the mixture was cooled, a small amount of precipitate was filtered, and then the solution was poured into methanol for reprecipitation. The polymer obtained is
According to IR analysis and NMR analysis, the siloxane-based polymer has the structure of R ₁ = deuterated phenyl group or deuterated pentyl group in the general formula (I) and M ₂ = Al structure in the general formula (V). It could be confirmed. The molecular weight of the obtained polymer was Mw = 91000 and n = 1.53.

(Polymer Production Example 10) 100 mg of KOH was added to 15 g of diphenyldichlorosilane d-10 and 1.3 g of diphenyldichlorogermanium to obtain 15 ml.
Of toluene. Then, this mixed liquid was refluxed for 16 hours. After completion of the reaction, the mixture was cooled, a small amount of precipitate was filtered, and then the solution was poured into methanol for reprecipitation. The polymer obtained has the general formula (III): R ₁ = R
₂ = structure of deuterated phenyl group and M _{1 in the} general formula (IV)
= Ge, R ₃ = R ₄ = It was confirmed by IR analysis and NMR analysis that it was a siloxane-based polymer having a phenyl group structure. The molecular weight of the obtained polymer is Mw = 10.
It was 6000 and n = 1.52.

(Polymer Production Example 11) Contents In a flask of about 100 ml, 100 g of KOH was added to 10 g of phenyltriethoxysilane and 1.3 g of aluminum chloride, and 1
Mix with 5 ml of toluene. Then, add this mixed solution to 1
Refluxed for 6 hours. After completion of the reaction, the mixture was cooled, a small amount of precipitate was filtered, and then the solution was poured into methanol for reprecipitation. The resulting polymer has the general formula (I) R ₁ =
It was confirmed by IR analysis and NMR analysis that it was a siloxane-based polymer having a structure of a phenyl group and a structure of M ₂ = Al in the general formula (V). The molecular weight of the polymer is M
w = 114000 and Mw / Mn = 6.1. The refractive index of this polymer was 1.60.

[0038]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

Example 1 Polymer The polymer obtained in Production Example 1 was dissolved in methyl isobutyl ketone and applied on a silicon substrate to a thickness of 13 μm by spin coating. Then, it was baked at 250 ° C. for 1 hour. 2 in an electric furnace at 1100 ° C in the presence of oxygen
Heated for hours. 1 in the infrared absorption spectrum of the film after heating
The absorption attributed to C-H such as 600 cm ^-1 had disappeared. The refractive index of the obtained film was 1.48.

Examples 2 to 11 As in Example 1, the polymers obtained in Polymer Production Examples 2 to 11 were formed into films, which were each heated in an electric furnace to be vitrified. Table 2 shows the refractive index of the obtained film.

[0041]

[Table 2]

Example 12 Polymer The polymer obtained in Production Example 1 was dissolved in methyl isobutyl ketone and coated on a silicon substrate to a thickness of 3 μm by spin coating. Then, it was baked at 250 ° C. for 1 hour. Further, it was placed in a cylindrical plasma etching apparatus and treated with oxygen as a reactive gas under the conditions of 1 Torr and 250 W for 30 minutes. In the infrared absorption spectrum of the film after the treatment, the absorption attributed to C—H such as 1600 cm ⁻¹ disappeared. The refractive index of the obtained film was 1.48. Example 13 A waveguide having the film obtained in Example 1 as a core component and the film obtained in Example 5 as a clad component was produced.

The above two polymers were dissolved in methyl isobutyl ketone to prepare a solution. First, a clad component polymer was applied on a silicon substrate to a thickness of about 20 μm. Bake,
After the drying treatment, it was vitrified by heating at 1100 ° C. in an electric furnace.
Further, a core component polymer was applied on the clad component to a thickness of about 13 μm, and similarly vitrified. Next, the core component polymer was processed into a linear rectangular pattern having a length of 50 mm and a width of 8 μm by photolithography and dry etching.
After processing, the clad component was applied onto the core component and vitrified to obtain a waveguide. The loss of the waveguide was calculated by irradiating light with wavelengths of 1300 nm and 1500 nm from one end of the waveguide and measuring the amount of light emitted from the other end. The loss of this waveguide is 0.01 dB / cm or less, and it is considered that it can be sufficiently applied to various optical circuits.

[0044]

As described above, the waveguide film according to the present invention can control the refractive index in a wide range by changing the metal content as compared with the conventional waveguide film. Further, it has excellent light transmission characteristics in the visible to near-infrared light region, and the loss increase is extremely small even when exposed to high temperature and high humidity conditions. Further, the refractive index is easily controlled, and therefore, it is suitable as a material for an optical integrated circuit in the near infrared light region. Further, since it has a low loss in the wavelength range of 650 to 1600 nm which has been conventionally used for optical fiber communication, it can be used for connection with multi-component glass and silica optical fibers without optical / electrical / electrical / optical conversion. In other words, an optical component manufactured using these optical materials can form a highly economical local network.

Claims (3)

[Claims] 1. The following general formula (I): [Wherein R ₁ is an alkyl group represented by C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, or C ₆ Y ₅ (Y is hydrogen, deuterated or halogen), a repeating unit represented by the following general formula (I
I): [Wherein M ₁ is a tetravalent element excluding Si, R ₂ is C _n Y _{2n + 1}
(Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, or C ₆ Y ₅ (Y is hydrogen, deuterium or halogen) And a repeating unit represented by the following formula: phenyl group, deuterated or halogenated phenyl group], and a waveguide film comprising a glass derived from a siloxane polymer. 2. The following general formula (III): [Wherein R ₁ and R ₂ are the same or different, and are C _n Y
_{2n + 1} (Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, or C ₆ Y ₅ (Y is hydrogen,
A phenyl group represented by deuterium or halogen), a repeating unit represented by a deuterated or halogenated phenyl group] and the following general formula (IV): [Wherein M ₁ is a tetravalent element excluding Si, R ₃ and R ₄ are the same or different, and are C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, and n is a positive integer of 5 or less). An alkyl group represented by, a deuterated or halogenated alkyl group, or a phenyl group represented by C ₆ Y ₅ (Y is hydrogen, deuterium or halogen), a deuterated or halogenated phenyl group] A waveguide film comprising a glass derived from a siloxane-based polymer having a repeating unit of 3. The following general formula (I): [Wherein R ₁ is an alkyl group represented by C _n Y _{2n + 1} (Y is hydrogen, deuterium or halogen, n is a positive integer of 5 or less), a deuterated or halogenated alkyl group, or C ₆ A phenyl group represented by Y ₅ (Y is hydrogen, deuterium or halogen), a deuterated or halogenated phenyl group] and the following general formula (V): A waveguide film comprising a glass derived from a siloxane polymer having a repeating unit represented by the formula: M ₂ is a trivalent element excluding rare earths.