JPH02307832A - Method for manufacturing semiconductor-doped glass thin film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a semiconductor-doped glass thin film, and more particularly, to a semiconductor doped glass thin film in which a compound or an elemental semiconductor is embedded and dispersed with a high particle size distribution by sputtering. This paper relates to doped glass thin films and their manufacturing methods.

(Prior Art and Problems to Be Solved) In recent years, with the development of high-power lasers, nonlinear optical materials have been attracting attention as peripheral devices.

In particular, semiconductor-doped glass not only exhibits high nonlinearity that surpasses organic highly nonlinear materials in terms of third-order nonlinearity;
Optical bistability of the psec response has also been discovered, and there is interest in the possibility of its application as optical shutters, optical switches, or optical high-speed devices.

However, as such semiconductor-doped glasses, there have been only a few reports on bulk materials used as filter glasses. In other words, the bulk material obtained by precipitation → rapid cooling is Sio, and the base material contains C.
dSxSe, -x semiconductors, etc. have a particle size of 20 to 100.
．． 1. There is one spot embedded around mo1%, and at most 2+
It is in the form of flakes with a thickness of io+, and the particle size is adjusted by annealing.

Moreover, these reports are limited to research reports on properties using bulk materials.

It is no exaggeration to say that there is no manufacturing method.

Considering future use, the bulk material is too thick, the types of semiconductors to be doped are limited to those listed above, and the grain size is large, making it impossible to control the grain size distribution uniformly. Therefore, its range of use is limited.

The present invention has been made in view of the above circumstances, and
The object of the present invention is to provide a semiconductor-doped glass thin film in the form of a thin film in which ultrafine particles of various compound semiconductors are dispersed in SiO□ glass with a high particle size distribution, and to provide a method for producing the same. be.

(Means for Solving the Problems) In order to achieve the above object, the inventors first studied a technique for thinning semiconductor-doped glass.

A vapor phase method can be considered as a method for obtaining a thin film, but among these, it is difficult to make SIO and glass amorphous using a vapor deposition method. In this regard, since it is easy to make the material amorphous by sputtering, we have conducted further intensive research on sputtering.

As a result, by sputtering with a rare gas such as Ar, ultrafine particles of compounds or single semiconductors can be dispersed at high concentrations with uniform particle sizes in Sin and glass without any restrictions on their component systems. Moreover, it has been found that a thin film that does not require annealing can be obtained. Furthermore, since the particle size can be controlled arbitrarily and a quantum size effect can be obtained, the range of use can be significantly expanded compared to that of bulk materials, and the present invention has been made based on this finding.

That is, the semiconductor-doped glass thin film according to the present invention has S
io, amorphous glass is characterized in that compound or single semiconductor fine particles each having a particle diameter of 100 Å or less and a content of 1 mol % or more are uniformly dispersed.

In addition, the present invention relating to the manufacturing method includes placing a compound or single semiconductor polycrystal on a target made of Sin,
By sputtering using a gas such as r, S
io, a method for controlling the semiconductor particle size distribution of a semiconductor-doped glass thin film, which is characterized by obtaining a semiconductor-doped glass thin film in which a compound or an elemental semiconductor with a uniform particle size is dispersed in the glass, and further annealing as necessary. That is.

The present invention will be explained in more detail below.

(Function) In sputtering according to the present invention, 5iO1 is used as a target, and a compound or single semiconductor chip is placed on this target. However, it is necessary to use at least a gas such as Ar, and the introduced gas can separate the compound or single semiconductor chip. By hitting the target, the ultrafine compound or elemental semiconductor can be uniformly dispersed in the amorphous Sio2 glass.

The compound or single semiconductor is not particularly limited, and compounds containing an element that is heavy and difficult to intensify, such as Sin, which is an unfamiliar element, are particularly preferable. For example, CdT
e, CdS, CdSe, ZnS, ZnTe, ZnSe,
PbI2, InP, Cd5nPz, CdSxSe, -x
, ZnGeAs,, 0 clauses As, Si, S
Examples include i-Ge, InSb, CuCl, and the like. Among these, CdTe, CdS, CdSe, ZnS, Z
nTe.

Zn5e, GaAs, etc. have the double wave of YAG laser (~2
．． 3sV), InP, Cd5nP, ZnGe
As, etc. are matched to the first harmonic wave (~1.2 eV).

Although the sputtering conditions are not particularly limited, the following are conditions that are desirable mainly for controlling the particle size distribution.

Since the higher the substrate temperature, the smaller the particle size becomes, the particle size distribution can also be controlled by the substrate temperature. Although the heating temperature depends on the type of compound or single semiconductor to be doped, a temperature of about 400° C. is also possible. Note that the substrate can also be water-cooled.

Regarding the number and position of compound or single semiconductor chips placed on the target, one or more chips may be placed in the center or near the center of the target, or multiple chips may be placed on the target at equal intervals or symmetrically. (For example, it is preferable to place it in a circular shape).

The number of chips (target area ratio) affects the content and particle size of the compound or single semiconductor, and as the number increases, the particle size increases, and ultrafine semiconductor particles of 100 Å or less can be obtained, and particle sizes of 15 Å or less can also be obtained. It is possible. The narrower the spacing between the chips, the more compounds or elemental semiconductors can be contained in the resulting sample. 1% or more can be dispersed. Note that the target area ratio can be 1% or more, and the larger the number, the larger the particle size.

Thin film thickness is controlled by sputtering time.

Can be rolled.

Other conditions are 150-200W, 1O-3To
rr level, and a rare gas such as Ar is usually used as the sputtering gas.

Note that the semiconductor-doped glass thin film obtained by sputtering does not need to be annealed, but if annealed, the grain size increases with processing time.

The semiconductor-doped glass thin film thus obtained is.

In Sio2 amorphous glass, particle size of 100 Å or less,
It has a property that the compound or single semiconductor fine particles containing 1 mol % or more are uniformly dispersed.

Since this semiconductor-doped glass thin film has a sharper optical absorption edge than conventional bulk materials, it is expected that it will exhibit the same characteristics as bulk materials when used, for example, as an optical switch.

(Example) Next, examples of the present invention will be shown.

2 to 6 CdT in the center of the target consisting of Yuko Sin,
Place the semiconductor chip, 200W, substrate temperature 240℃,
Sputtering was performed with Ar under conditions of 5×10 − Torr to obtain a semiconductor-doped thin film.

Regarding the number of chips, in Fig. 1, a is 3 and b is 3.
There are 4 pieces of C and 6 pieces of C, each placed in the center of the target.
d is the case where two chips are placed equidistantly from the center of the target, and the target area ratio is a.
is 3.1%, b is 4°2%, C is 6.3%, d is 2.1
%.

FIG. 1 shows the optical absorption edge of each sample. Note that the optical absorption edge is the relationship between transmittance and energy gap, which is obtained by overlapping Sio and a sample and determining the energy gap from the ratio (transmittance) of the incident light entering from the sample side and the reflected light. , the vertical axis of the figure is the transmittance (%), and the horizontal axis is the optical energy (e V ).

From FIG. 1, it can be seen that the semiconductor-doped thin film has better properties than the bulk material, and that the smaller the particle size, the more the energy gap shifts to the higher energy side, and the quantum size effect is obtained. The shift was approximately proportional to the reciprocal of the square of the radius, confirming that it fits the theory. FIG. 2 shows the results of X-ray diffraction of the sample.

In addition, the average particle size of semiconductor particles in the obtained sample is
11 X-rays showed that there were 22 people in A, 27 in B, and 27 people in C.
There were 41 people in ``D'' and 62 people in ``D''.

In addition, FIG. 3 shows sample a in FIG. 1 after annealing (60
The graph shows the optical absorption edge when annealing (0"C ), it can be seen that excellent characteristics can be obtained.

2 to 8 CDs in the center of the target consisting of abortive five-pronged Sin,
A Se semiconductor chip was placed, and sputtering was performed with Ar under the conditions of 150 to 200 W, a substrate temperature of 240° C., and 5×10″3 Torr to obtain a semiconductor doped thin film.

The optical absorption edge of each sample is shown in Figure 4. In Figure 4, the average particle size is 15 Å or less depending on the number of chips (curve at the right end of the figure).
The number of cases varied from 1 to 26.

From FIG. 4, it can be seen that as the number of chips increases, the particle size increases and the optical absorption edge shifts to the lower energy side.

Eight CdS semiconductor chips were placed in a circular shape on a target made of SiO□, 200W, substrate temperature = 200°C,
150℃, water cooling, 5 x 10-”
Sputtering was performed with Ar under Torr conditions to obtain a semiconductor-doped thin film.

As shown in FIG. 5, the optical absorption edge of each sample shows that the higher the substrate temperature, the smaller the particle size and the shift toward higher energy. In addition, the average particle diameter is 27 people for a, and
4, 6, or 8 GaAs semiconductor chips were placed in a circular shape on a target consisting of 31 people and 53 people in C. 2゜OW, substrate temperature: water cooling. , 5 X 10-3 Torr, sputtering time: 30 m1n (number of chips: 4, 6), 60 m1n (
Sputtering was performed with Ar under the condition of 8 chips) to obtain a semiconductor-doped thin film.

FIG. 6 shows the optical absorption edge of each sample. In addition, the average particle diameter is 1 (number of chips: 4, target area ratio: 4.1%).
5 people, b (6 chips, target area ratio 6.2%)
22 people, C (number of chips 8, target area ratio 8.3
%) were 26 people.

From Figure 6, as the target area ratio increases, the particle size increases and the energy gap shifts to the lower energy side.
It can be seen that there is a dependence on the target area ratio.

Further, in the case where the number of chips is 8, the substrate temperature was changed to 150° C., 250° C., and 400° C., and the dependence of the optical absorption edge on the substrate temperature was investigated. As in the case of Example 5, as shown in FIG. 7, the results show that the higher the substrate temperature is, the smaller the particle size is, and the energy gap is shifted to the higher energy side.

Nu IL Ji A ZnS semiconductor chip is placed on a target consisting of Sin.

200W, substrate temperature: water cooling, 5 x 1 for the case where one lump is placed in the center and the case where 100 pieces are placed in a circular shape.
A under the conditions of 0-' Torr and sputtering time: 60 m1n.
Sputtering was performed at r to obtain a semiconductor doped thin film.

FIG. 8 shows the optical absorption edge of each sample. In addition, the average particle diameter was 36 for a (1 chip, target area ratio ↓%) and 5 for b (10 chips, 10% target area ratio).
There were 5 people.

From Figure 8, as the number of chips increases, the particle size increases and the energy gap shifts to the lower energy side.
Similar results were obtained as in Example 2.4.

200 W, substrate temperature: 250°C, water cooling, 5 x 10'' when two ZnTe semiconductor chips were placed in the center on a target made of SiO2, and when four or eight ZnTe semiconductor chips were placed in a circular shape. "3 Torr, sputtering time = 20~30
Sputtering was performed with Ar under conditions of m1n to obtain a semiconductor-doped thin film.

FIG. 9 shows the optical absorption edge of each sample in relation to the particle size of the compound semiconductor particles. In addition, the average particle size was 28 people for a (2 chips, 250°C substrate temperature, 2% target area ratio), 32 people for / (2 chips, water-cooled board, 2% target area ratio), and 32 people for / (2 chips, water-cooled board, 2% target area ratio). (4 chips, target area ratio 4%) was selected by 59 people, and C (8 chips, target area ratio 8%) was selected by 93 people.

From FIG. 9, as the number of chips increases, the particle size increases, and as the substrate temperature increases, the particle size decreases.

From the experimental results of the above examples, the energy gap of the semiconductor-doped glass thin film is determined by the compound semiconductor particle size,
It has been found that the following method can be used to control the particle size.

(2) By increasing the area of the compound semiconductor chip on the Sio2 target (target area ratio), the particle size can be controlled to be large while keeping it uniform.

■ Particle size can be increased with annealing time.

(2) By increasing the substrate temperature, it is possible to greatly control the grain size while keeping it uniform.

Among the samples obtained in Example 2, a laser was applied to a sample (compound semiconductor: Cd5e) with a particle size of 26, and the PL (electron and hole) from the time the laser was cut (time: Qpsec) was calculated. We investigated the relationship between the intensity of the light emitted by recombination (the light emitted by recombination), the emission wavelength, and time.

As shown in FIG. 10, the results show that light with a wavelength of 551 nm has the highest intensity and disappears at 65 Q psec. The current shortest switching time requires 40 psec to turn off, but compared to 10 n5ec to 10' psec for bulk materials, it has been confirmed that this is extremely short, and it will be used as a high-speed optical shutter, optical switch, etc. It can be seen that it is fully usable.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to make semiconductor-doped glass into a thin film, but it also causes problems such as restrictions on the type and content of semiconductors as in conventional bulk materials. It is possible to disperse ultrafine particles of compounds or elemental semiconductors with uniform particle sizes in Sin or glass without any problems, and furthermore, the particle size can be controlled, which significantly promotes industrial use.

Therefore, as in the case of bulk materials, it is possible to provide semiconductor-doped glass thin films that have not only high nonlinearity but also optical bistability of pseC response superior to bulk materials, so they can be used in optical shutters, optical switches, or optical high-speed response devices. It is fully expected that it will be applied as a.

[Brief explanation of drawings]

Figure 1 shows the optical absorption edge of a semiconductor (CdTe) doped glass thin film, Figure 2 shows the X-ray diffraction results of the thin film, and Figure 3 shows the annealing time dependence of some of the thin films. 4 and 5 are diagrams showing the optical absorption edge of a semiconductor (CdSe) doped glass thin film, FIGS. 6 and 7 are diagrams showing the optical absorption edge of a semiconductor (GaAs) doped glass thin film, Figure 8 shows the optical absorption edge of a semiconductor (ZnS) doped glass thin film, Figure 9 shows the optical absorption edge of a semiconductor (ZnTe) doped glass thin film, and Figure 10 shows the optical absorption edge of a semiconductor (CdSe) doped glass thin film. FIG. 3 is a diagram showing the relationship between the emission wavelength of the PL intensity and time after the laser is applied and the laser is turned off. Patent applicant Naomitsu Nakamura, patent attorney representing the New Technology Development Corporation Direct gun prison (〃) Ri Futei Naoki C'/-) Transparent ¥ ('/,)

Claims (8)

[Claims] (1) By placing a compound or single semiconductor polycrystal on a target made of SiO_2 and sputtering using a gas such as Ar, a semiconductor-doped glass thin film in which a compound or single semiconductor with a uniform particle size is dispersed in SiO_2 glass A method for controlling semiconductor grain size distribution in a semiconductor-doped glass thin film, characterized in that it obtains the following: (2) The compound or single semiconductor is CdTe, CdS,
CdSe, ZnS, ZnTe, ZnSe, PbI_2,
InP, CdSnP_2, CdSxSe_1_-_x,
ZnGeAs_2, GaAs, Si, Si-Ge, In
The method according to claim 1, comprising one of Sb and CuCl. (3) The method according to claim 1, wherein the particle size is controlled by changing the number of compounds or single semiconductor chips placed on the target. (4) The method according to claim 1 or 3, wherein the particle size of the compound or single semiconductor is controlled by changing the sputtering operation and the substrate temperature. (5) claim 1, wherein the particle size of the compound or single semiconductor is controlled by annealing the semiconductor-doped glass thin film;
The method described in 3 or 4. (6) Particle size 100 in SiO_2 amorphous glass
A semiconductor-doped glass thin film characterized in that compound or single semiconductor fine particles having a content of 1 mol % or more are uniformly dispersed. (7) The semiconductor-doped glass thin film according to claim 6, wherein the compound or single semiconductor is doped by sputtering using a gas such as Ar. (8) The semiconductor-doped glass thin film according to claim 6 or 7, wherein the compound or single semiconductor is doped by sputtering using a gas such as Ar and annealed.