JPH0672800B2 - Pyroelectric infrared sensor - Google Patents
Pyroelectric infrared sensorInfo
- Publication number
- JPH0672800B2 JPH0672800B2 JP61054058A JP5405886A JPH0672800B2 JP H0672800 B2 JPH0672800 B2 JP H0672800B2 JP 61054058 A JP61054058 A JP 61054058A JP 5405886 A JP5405886 A JP 5405886A JP H0672800 B2 JPH0672800 B2 JP H0672800B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- pyroelectric
- substrate
- mgo
- infrared sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000010409 thin film Substances 0.000 claims description 57
- 239000000758 substrate Substances 0.000 claims description 33
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 9
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 8
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 description 9
- 239000013078 crystal Substances 0.000 description 6
- 230000010287 polarization Effects 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 5
- 239000005350 fused silica glass Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 230000005616 pyroelectricity Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
- G01J5/34—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using capacitors, e.g. pyroelectric capacitors
Description
【発明の詳細な説明】 産業上の利用分野 本発明は焦電型赤外線センサに関する。TECHNICAL FIELD The present invention relates to a pyroelectric infrared sensor.
従来の技術 焦電型赤外線センサはセンサからの熱伝導が小さいほど
高感度になるため、熱伝導を小さくするため様々な方法
が試みられている。2. Description of the Related Art A pyroelectric infrared sensor has higher sensitivity as the heat conduction from the sensor is smaller. Therefore, various methods have been tried to reduce the heat conduction.
従来の焦電体薄膜を用いた赤外線センサの構成を第２図
に示す。基板１上に下部電極２を形成し、下部電極２上
に焦電体薄膜３を形成し、焦電体薄膜３上に上部電極４
を形成し、前記基板１のうち上部電極４の下方に位置す
る部分５が取り除かれている。前記基板１の一部を取り
除くことにより熱伝導をおさえている。一方、基板１と
して低熱伝導率材料を用いて基板１を取り除かないもの
がある。（奥山ら，第２回センサシンポジウム論文集,1
982,pp.94〜53） また焦電体薄膜自体の感度特性向上のために、基板１に
単結晶を用い焦電体薄膜３として配向薄膜つまり分極軸
の揃った薄膜を用いている焦電型赤外線センサがある。
（飯島ら，第３回センサシンポジウム論文集,1983,pp.1
33〜136） 発明が解決しようとする問題点 薄膜を用いた焦電型赤外線センサは、熱伝導を小さくす
るために基板１の一部を取り除かなくてはならない。し
かし基板１を取り除くことにより焦電体薄膜を力学的に
弱くなる。また、基板１を取り除かない焦電型薄膜赤外
線センサは、基板１として低熱伝導率材料を用いなくて
はならず、このような基板１上には飯島らの従来例のご
とく性能指数（焦電係数／誘電率）が５×10-8c/cmK以
上と優れた特性の焦電体薄膜が現在のところ得られてい
ない。FIG. 2 shows the structure of a conventional infrared sensor using a pyroelectric thin film. The lower electrode 2 is formed on the substrate 1, the pyroelectric thin film 3 is formed on the lower electrode 2, and the upper electrode 4 is formed on the pyroelectric thin film 3.
And a portion 5 of the substrate 1 located below the upper electrode 4 is removed. Heat conduction is suppressed by removing a part of the substrate 1. On the other hand, there is a substrate 1 that uses a low thermal conductivity material and does not remove the substrate 1. (Okuyama et al., Proceedings of the 2nd Sensor Symposium, 1
982, pp.94-53) Also, in order to improve the sensitivity characteristics of the pyroelectric thin film itself, a single crystal is used for the substrate 1 and an oriented thin film, that is, a thin film with a uniform polarization axis is used as the pyroelectric thin film 3. There is a type infrared sensor.
(Iijima et al., Proc. Of the 3rd Sensor Symposium, 1983, pp.1
33-136) Problems to be Solved by the Invention In a pyroelectric infrared sensor using a thin film, a part of the substrate 1 must be removed in order to reduce heat conduction. However, removing the substrate 1 mechanically weakens the pyroelectric thin film. In addition, the pyroelectric thin-film infrared sensor in which the substrate 1 is not removed must use a low thermal conductivity material as the substrate 1, and such a performance index (pyroelectricity) as in the conventional example of Iijima et al. A pyroelectric thin film having excellent characteristics such as a coefficient / dielectric constant of 5 × 10 -8 c / cmK or more has not been obtained at present.
一方、単結晶基板上に配向した焦電体薄膜を作成した場
合、分極軸が揃うため高感度な赤外線センサが得られ
る。しかし、配向に適した基板材料は限定され、さらに
単結晶は概ね高熱伝導率であるため基板１を取り除かな
くてはならず、力学的に弱くなる。On the other hand, when the oriented pyroelectric thin film is formed on the single crystal substrate, the polarization axes are aligned, so that a highly sensitive infrared sensor can be obtained. However, the substrate material suitable for orientation is limited, and since the single crystal generally has high thermal conductivity, the substrate 1 must be removed, which is mechanically weak.
本発明は上記問題点を解決するもので、低熱伝導率の基
板上に焦電体薄膜を配向させ、基板を取り除かず力学的
に強く、高感度な焦電型赤外線センサを提供することを
目的とするものである。The present invention solves the above problems, and an object of the present invention is to provide a pyroelectric infrared sensor which has a pyroelectric thin film oriented on a substrate having a low thermal conductivity, is mechanically strong without removing the substrate, and has high sensitivity. It is what
問題点を解決するための手段 MgOよりも低熱伝導率の酸化硅素を主成分とする基板
と、基板上に形成したMgO薄膜と、MgO薄膜上に形成した
焦電体薄膜とを備え、前記MgO薄膜を配向させる。Means for Solving the Problems A substrate containing silicon oxide as a main component having a lower thermal conductivity than MgO, an MgO thin film formed on the substrate, and a pyroelectric thin film formed on the MgO thin film are provided. Orient the thin film.
作用 上記手段のように基板上に配向したMgO薄膜を配するこ
とにより、分極方向に配向した焦電体薄膜を作成するこ
とができるようになり、さらに低熱伝導率の基板を用
い、この基板を取り除くことなく従来（飯島らの従来
例）のMgO単結晶上に配向した焦電体薄膜と同様の性能
指数を示し、高感度な焦電型赤外線センサが得られる。By arranging the oriented MgO thin film on the substrate as in the above means, it becomes possible to create a pyroelectric thin film oriented in the polarization direction. Without removing it, it shows the same figure of merit as the conventional pyroelectric thin film oriented on MgO single crystal (Iijima et al.), And a highly sensitive pyroelectric infrared sensor can be obtained.
実施例 第１図に本発明の一実施例を示す。基板６上にMgO薄膜
７を形成し、MgO薄膜７上に下部電極８を形成し、下部
電力８上に焦電体薄膜９を形成し、焦電体薄膜９上に上
部電極10を形成したものである。Embodiment FIG. 1 shows an embodiment of the present invention. The MgO thin film 7 was formed on the substrate 6, the lower electrode 8 was formed on the MgO thin film 7, the pyroelectric thin film 9 was formed on the lower power 8, and the upper electrode 10 was formed on the pyroelectric thin film 9. It is a thing.
基板６として溶融石英を用い、この上にMgO薄膜７をRF
マグネトロンスパッタリングにより作製した。このMgO
薄膜７は特定の条件の下で（100）配向することが確認
された。この条件を表１に示す。さらに前記MgO薄膜７
上に（100）配向した白金薄膜を作製して下部電極８と
した。上記MgO薄膜７はまた、溶融石英上に形成したア
モルファス白金上においても（100）配向した。溶融石
英は酸化硅素よりなる石英ガラスであり、その熱伝導率
は、1.38k/Wm-1K-1（室温）であってMgOや半導体よりも
大幅に低い。The fused quartz is used as the substrate 6, and the MgO thin film 7 is RF-coated thereon.
It was produced by magnetron sputtering. This MgO
It was confirmed that the thin film 7 was (100) oriented under specific conditions. This condition is shown in Table 1. Furthermore, the MgO thin film 7
A (100) -oriented platinum thin film was formed on the upper surface of the lower electrode 8. The MgO thin film 7 was also (100) oriented on amorphous platinum formed on fused silica. Fused silica is silica glass made of silicon oxide, and its thermal conductivity is 1.38 k / Wm -1 K -1 (room temperature), which is significantly lower than MgO and semiconductors.
焦電体材料としては、PbxLayTizZrwO3で表される材料を
用いた。なおx,y,z,wは次の範囲から選択された。 As the pyroelectric material, a material represented by PbxLayTizZrwO 3 was used. Note that x, y, z, and w were selected from the following range.
ａ）0.7≦ｘ≦１ 0.9x＋ｙ≦１ 0.95≦ｚ≦１ ｗ＝
０ ｂ）ｘ＝１ ｙ＝０ 0.45≦ｚ＜１ ｚ＋ｗ＝１ ｃ）0.83≦ｘ≦１ ｘ＋ｙ＝１ 0.5≦ｚ＜１ 0.96≦
ｚ＋ｗ≦１ 上記の焦電体材料は特性が優れており、高感度の焦電型
赤外線センサを得ることができ、さらに分極軸を揃える
ことにより感度向上を図ることができる。また、下記組
成における上記焦電体材料は正方晶となり分極軸が（00
1）方向であるため、（001）配向させることによりさら
に電圧感度の高い焦電型赤外線センサを得ることができ
る。a) 0.7 ≦ x ≦ 1 0.9x + y ≦ 1 0.95 ≦ z ≦ 1 w =
0 b) x = 1 y = 0 0.45 ≦ z <1 z + w = 1 c) 0.83 ≦ x ≦ 1 x + y = 1 0.5 ≦ z <1 0.96 ≦
z + w ≦ 1 The above pyroelectric material has excellent characteristics, and a highly sensitive pyroelectric infrared sensor can be obtained. Further, the sensitivity can be improved by aligning the polarization axes. Further, the above pyroelectric material having the following composition is tetragonal and has a polarization axis of (00
Since it is in the 1) direction, the (001) orientation makes it possible to obtain a pyroelectric infrared sensor with higher voltage sensitivity.
焦電体薄膜９として、ｘ＋ｙ＝1,z＝１−x/4,w＝０であ
る材料を用いて試料を作製し、（001）配向しているこ
とを確認した。この材料を用いた焦電体薄膜９は、表１
に示す作製条件の下にスパッタリング法を用いることに
よって、MgOの（100）面、または（100）配向した白金
上に高度に配向させることができる。これら３種類の薄
膜の作製条件を表１にまとめて示す。As the pyroelectric thin film 9, a sample was prepared using a material of x + y = 1, z = 1-x / 4, w = 0, and it was confirmed that the sample had a (001) orientation. Pyroelectric thin film 9 using this material is shown in Table 1.
By using the sputtering method under the manufacturing conditions shown in (1), it is possible to highly orientate the MgO on the (100) plane or on the (100) -oriented platinum. The production conditions for these three types of thin films are summarized in Table 1.
作製した焦電体薄膜９のＸ線回折を測定した。その結果
（001）と（100）以外の信号は殆ど観測されず、どちら
かに配向した微結晶の集合となっていることがわかる。
（100）、（001）それぞれのピークにおけるＸ線強度を
I(100)、I(001)とし、次式に示すαを（001）配向率と
して、各Ｘについてのαを求めた。この結果を表２に示
す。The X-ray diffraction of the produced pyroelectric thin film 9 was measured. As a result, almost no signals other than (001) and (100) were observed, indicating that the crystals were aggregates oriented in either direction.
X-ray intensity at each peak of (100) and (001)
With respect to I (100) and I (001) , α shown in the following equation was taken as a (001) orientation ratio, and α for each X was obtained. The results are shown in Table 2.
α＝I(100)/（I(100)＋I(001)） 実施例として下部電極８がMgO薄膜７と焦電体薄膜９の
間に存在する焦電型赤外線センサを示したが、MgO薄膜
７が十分薄い場合、下部電極８が基板６とMgO薄膜７の
間に存在する構成も考えられる。この場合下部電極８は
配向している必要はなくプロセスが簡単になるが、電極
間に絶縁物であるMgO薄膜７をはさんでいることに対す
る注意が必要である。α = I (100) / (I (100) + I (001) ) As an example, the pyroelectric infrared sensor in which the lower electrode 8 is present between the MgO thin film 7 and the pyroelectric thin film 9 is shown, but when the MgO thin film 7 is sufficiently thin, the lower electrode 8 is composed of the substrate 6 and the MgO thin film 7. A structure existing in between may be considered. In this case, the lower electrode 8 does not need to be oriented and the process is simplified, but attention must be paid to the fact that the MgO thin film 7 as an insulator is sandwiched between the electrodes.
以上のように、MgOよりも大幅に小さな熱伝導率を有し
酸化珪素を主成分とする基板である溶融石英基板上に配
向したMgO薄膜を作製し、その上に良質な焦電体薄膜を
形成することにより、基板の熱伝導率がMgO単結晶より
も格段小さいため、基板を取り除かずとも高感度で力学
的に強い高感度な焦電型赤外線センサを得ることができ
る。As described above, an oriented MgO thin film was prepared on a fused silica substrate, which is a substrate whose main component is silicon oxide and has a thermal conductivity significantly lower than that of MgO, and a high-quality pyroelectric thin film was formed on it. By forming the substrate, the thermal conductivity of the substrate is much smaller than that of the MgO single crystal, so that a highly sensitive and mechanically strong pyroelectric infrared sensor can be obtained without removing the substrate.
発明の効果 本発明によれば、低熱伝導の基板上に高度に配向したMg
O薄膜を作成することにより、配向し性能指数が大きく
かつ、分極軸の揃った焦電体薄膜を作成することがで
き、基板を取り除く必要もなく力学的に強く、高感度な
焦電型赤外線センサが得られる。EFFECTS OF THE INVENTION According to the present invention, highly oriented Mg on a substrate of low thermal conductivity.
By forming an O thin film, it is possible to form a pyroelectric thin film that is oriented, has a large figure of merit, and has a uniform polarization axis, and is a mechanically strong and highly sensitive pyroelectric infrared without the need to remove the substrate. A sensor is obtained.
第１図は本発明の一実施例における焦電型赤外線センサ
の断面図、第２図は従来例を示す断面図である。 ６……基板、７……MgO薄膜、８……下部電極、９……
焦電体薄膜、10……下部電極。FIG. 1 is a sectional view of a pyroelectric infrared sensor according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. 6 ... Substrate, 7 ... MgO thin film, 8 ... Lower electrode, 9 ...
Pyroelectric thin film, 10 ... Lower electrode.
Claims (6)
上に形成した焦電体薄膜とを有し、前記MgO薄膜が配向
しているとともに前記基板がMgOよりも低熱伝導率であ
る酸化珪素を主成分とする基板であることを特徴とする
焦電型赤外線センサ。1. An MgO thin film formed on a substrate, and a pyroelectric thin film formed on the MgO thin film, wherein the MgO thin film is oriented and the substrate has a lower thermal conductivity than MgO. A pyroelectric infrared sensor, which is a substrate containing silicon oxide as a main component.
範囲第１項記載の焦電型赤外線センサ。2. The pyroelectric infrared sensor according to claim 1, wherein the MgO thin film has a (100) orientation.
０ ｂ）ｘ＝１ ｙ＝０ 0.45≦ｚ＜１ ｚ＋ｗ＝１ ｃ）0.83≦ｘ≦１ ｘ＋ｙ＝１ 0.5≦ｚ＜１ 0.96≦
ｚ＋ｗ≦１ のいずれかの組成を有する特許請求の範囲第１項記載の
焦電型赤外線センサ。3. A pyroelectric thin film is represented by PbxLayTizZrwO 3 , and a) 0.7 ≦ x ≦ 1 0.9x + y ≦ 1 0.95 ≦ z ≦ 1 w =
0 b) x = 1 y = 0 0.45 ≦ z <1 z + w = 1 c) 0.83 ≦ x ≦ 1 x + y = 1 0.5 ≦ z <1 0.96 ≦
The pyroelectric infrared sensor according to claim 1, which has a composition of any one of z + w ≦ 1.
求の範囲第１項記載の焦電型赤外線センサ。4. The pyroelectric infrared sensor according to claim 1, wherein the pyroelectric thin film is (001) oriented.
とMgO薄膜との間に形成した下部電極とを有する特許請
求の範囲第１項記載の焦電型赤外線センサ。5. The pyroelectric infrared sensor according to claim 1, further comprising an upper electrode formed on the pyroelectric thin film and a lower electrode formed between the substrate and the MgO thin film.
薄膜と焦電体薄膜との間に形成した下部電極を有し、前
記下部電極が（100）配向している白金薄膜であること
を特徴とする特許請求の範囲第１項記載の焦電型赤外線
センサ。6. An upper electrode formed on a pyroelectric thin film, and MgO.
The pyroelectric mold according to claim 1, further comprising a lower electrode formed between the thin film and the pyroelectric thin film, wherein the lower electrode is a (100) -oriented platinum thin film. Infrared sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61054058A JPH0672800B2 (en) | 1986-03-12 | 1986-03-12 | Pyroelectric infrared sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61054058A JPH0672800B2 (en) | 1986-03-12 | 1986-03-12 | Pyroelectric infrared sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62211520A JPS62211520A (en) | 1987-09-17 |
| JPH0672800B2 true JPH0672800B2 (en) | 1994-09-14 |
Family
ID=12960012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61054058A Expired - Fee Related JPH0672800B2 (en) | 1986-03-12 | 1986-03-12 | Pyroelectric infrared sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0672800B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2834355B2 (en) * | 1991-11-25 | 1998-12-09 | 松下電器産業株式会社 | Method of manufacturing ferroelectric thin film construct |
| US5413667A (en) * | 1992-11-04 | 1995-05-09 | Matsushita Electric Industrial Co., Ltd. | Pyroelectric infrared detector fabricating method |
| KR950001303A (en) * | 1993-06-22 | 1995-01-03 | 이헌조 | Thin film infrared sensor structure and manufacturing method |
| US5612536A (en) * | 1994-02-07 | 1997-03-18 | Matsushita Electric Industrial Co., Ltd. | Thin film sensor element and method of manufacturing the same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0685450B2 (en) * | 1986-01-13 | 1994-10-26 | 松下電器産業株式会社 | Ferroelectric thin film element |
-
1986
- 1986-03-12 JP JP61054058A patent/JPH0672800B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62211520A (en) | 1987-09-17 |
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