JPH05187917A - Infrared sensor - Google Patents
Infrared sensorInfo
- Publication number
- JPH05187917A JPH05187917A JP4002436A JP243692A JPH05187917A JP H05187917 A JPH05187917 A JP H05187917A JP 4002436 A JP4002436 A JP 4002436A JP 243692 A JP243692 A JP 243692A JP H05187917 A JPH05187917 A JP H05187917A
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- film
- pyroelectric
- diaphragm
- sensors
- 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.)
- Pending
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- Radiation Pyrometers (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は，入射赤外線変化量に応
じて電荷を発生する焦電膜を備えた赤外線センサに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared sensor provided with a pyroelectric film that generates electric charge according to the amount of change in incident infrared light.
【０００２】[0002]
【従来の技術】従来，赤外線センサの焦電素子は単結晶
又は多結晶の焦電材料を研磨によって薄片とし，その薄
片の両面に電極を形成し，熱伝導率が低い支持台に接着
して一方の電極からリード線を取り出し，素子の近傍に
配置された信号処理部に接続し，さらに外部に配置され
たメカニカルチョッパによって入力光を断続させること
により温度変化に関連した電気信号を得ている。2. Description of the Related Art Conventionally, a pyroelectric element of an infrared sensor is made into a thin piece by polishing a single crystal or polycrystalline pyroelectric material, electrodes are formed on both sides of the thin piece, and the thin piece is adhered to a supporting base having a low thermal conductivity. An electrical signal related to the temperature change is obtained by taking out a lead wire from one electrode, connecting it to a signal processing unit arranged near the element, and interrupting the input light by a mechanical chopper arranged outside. ..
【０００３】[0003]
【発明が解決しようとする課題】しかしながら，焦電材
料を薄片に加工するのは限界があり，そのため熱容量を
小さくすることは困難であった。また，組み立て工程が
煩雑であり，メカニカルチョッパーを使用しているため
形状が大きくなり，磨耗などによる故障も発生するとい
う問題があった。本発明は上記従来技術の問題点を解決
するためになされたもので，基板に形成したチョッパー
を面方向に駆動してチョッピングすることにより，小形
で磨耗部分がなく従って故障のない赤外線検出器を提供
するHowever, it is difficult to process the pyroelectric material into thin pieces, and it is difficult to reduce the heat capacity. In addition, the assembly process is complicated, and since the mechanical chopper is used, the shape becomes large, and there is a problem that a failure due to wear or the like occurs. The present invention has been made to solve the above-mentioned problems of the prior art. By driving a chopper formed on a substrate in the surface direction to perform chopping, a small infrared detector having no wear portion and therefore no failure is provided. provide
【０００４】[0004]
【課題を解決するための手段】上記課題を解決する本発
明の構成は，少なくとも２本の梁により支持されたダイ
アフラムと，このダイアフラム上に形成された絶縁膜
と，前記ダイアフラムと絶縁膜間に形成された断熱層
と，前記絶縁膜上に下部電極，焦電膜，上部電極および
光吸収膜が順次積層され，前記絶縁膜を含む前記積層さ
れた層が複数の長方形の孔により，アレイ状に分離され
た焦電センサを有する第１基板と，少なくとも２本の梁
に支持され前記第１基板の複数の焦電センサの形状とほ
ぼ同一形状に形成された複数のチョッパーと，これらの
チョッパーを面方向に駆動する駆動手段からなる第２基
板とからなり，前記第１基板上に第２基板を配設し，前
記焦電センサ上で前記チョッパーを面方向に往復駆動し
て前記焦電センサに入射する赤外線をチョッピングする
ように構成したことを特徴とするものである。The structure of the present invention for solving the above-mentioned problems is a diaphragm supported by at least two beams, an insulating film formed on the diaphragm, and a space between the diaphragm and the insulating film. The formed heat insulating layer, the lower electrode, the pyroelectric film, the upper electrode and the light absorbing film are sequentially stacked on the insulating film, and the stacked layers including the insulating film are arrayed by a plurality of rectangular holes. A first substrate having a pyroelectric sensor separated into two, a plurality of choppers supported by at least two beams and formed in substantially the same shape as the plurality of pyroelectric sensors of the first substrate, and these choppers A second substrate composed of driving means for driving the chopper in a plane direction, the second substrate is disposed on the first substrate, and the chopper is reciprocally driven in the plane direction on the pyroelectric sensor to perform the pyroelectricity. Enter the sensor It is characterized in that it has configured to chopping the infrared radiation.
【０００５】[0005]
【作用】センサアレイの幅とチョッパー部の孔幅がほぼ
同一形状に形成されており，チョッパーを面方向に駆動
する手段が設けられているので，チョッパーを焦電セン
サの幅の振幅で駆動すればセンサは交互に電気信号を発
生する。そして，焦電センサがダイアフラム上に断熱層
を介して形成されているので，熱容量を極めて小さくす
ることができ応答速度および感度が向上する。[Function] Since the width of the sensor array and the hole width of the chopper are formed to have substantially the same shape, and means for driving the chopper in the surface direction is provided, it is possible to drive the chopper at the amplitude of the width of the pyroelectric sensor. For example, the sensors alternately generate electrical signals. Further, since the pyroelectric sensor is formed on the diaphragm via the heat insulating layer, the heat capacity can be made extremely small, and the response speed and sensitivity are improved.
【０００６】[0006]
【実施例】以下，図面を参照して本発明を詳述する。図
１（ａ），（ｂ）および図（２）は本発明の一実施例を
示すもので，図１（ａ）は第１基板の構成斜視図，図１
（ｂ）は第２基板の構成斜視図，図２は図１（ａ）のＡ
ーＡ断面図である。これらの図において，１はシリコン
からなる第１基板であり，この基板の一面には異方性エ
ッチングにより形成された穴２（図２参照）により他方
の側の面で正方形のダイアフラム３が形成されている。
このダイアフラム３には角部の４カ所３1,３2,３3,34が
側面に沿ってＬ字状に除去され，中央部に正方形のセン
サアレイ４が形成されている（即ちセンサアレイ４は４
本の梁４1，４2,４3,４4により支持されている）。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 1 (a), 1 (b) and 2 (2) show an embodiment of the present invention. FIG. 1 (a) is a perspective view of the configuration of a first substrate, FIG.
FIG. 2B is a perspective view of the configuration of the second substrate, and FIG. 2 is A of FIG.
FIG. In these figures, reference numeral 1 denotes a first substrate made of silicon, and a square diaphragm 3 is formed on the other surface by a hole 2 (see FIG. 2) formed by anisotropic etching on one surface of this substrate. Has been done.
In this diaphragm 3, four corners 3 1, 3 2, 3 3, 3 4 are removed along the side surface in an L shape, and a square sensor array 4 is formed in the center (that is, the sensor array). 4 is 4
Is supported by the beams 4 1, 4 2, 4 3, 4 4 of the present).
【０００７】５はセンサアレイを含む基板全体に形成さ
れた絶縁膜（酸化膜又は窒化膜），６は絶縁膜の下部に
形成された正方形の空洞からなる断熱層である。絶縁膜
５の上にはＰｔ／Ｔｉからなる下部電極６a，ＰＬＴ
（ランタンを含むチタン酸鉛）からなる焦電膜７，Ａｕ
からなる上部電極８および金黒からなる光吸収膜９が順
次積層されている。１０は断熱層６に貫通して形成され
アレイ状の焦電センサ４ aを形成するための孔であり，
この孔１０の長さは断熱層６の辺の長さと同程度に形成
されている。１１は複数の上部電極８に接続された取り
出し電極（図１参照）であり，図では省略するが対向す
る側には下部電極６ａに接続された取り出し電極が形成
されている。5 is formed on the entire substrate including the sensor array.
Insulating film (oxide film or nitride film), 6 is formed under the insulating film.
It is a heat insulating layer consisting of a square cavity formed. Insulation film
5 is a lower electrode 6 made of Pt / Ti.a, PLT
Pyroelectric film 7 made of (lead lanthanum-containing titanate), Au
The upper electrode 8 made of gold and the light absorption film 9 made of gold black are in order.
Next is stacked. 10 is formed by penetrating the heat insulating layer 6.
Array pyroelectric sensor 4 aIs a hole for forming
The length of the hole 10 is formed to be approximately the same as the side length of the heat insulating layer 6.
Has been done. Reference numeral 11 is a connection connected to a plurality of upper electrodes 8.
Output electrode (see Fig. 1).
A take-out electrode connected to the lower electrode 6a
Has been done.
【０００８】なお，上記において焦電センサは例えば次
の様にして形成する。はじめにＰＺＴ溶液を作製する。
このＰＺＴ溶液は酸化鉛と無水酢酸を２メトキシエタノ
―ル溶液に溶解し，この溶解液にＺｒ，Ｔｉ，Ｓｎ，お
よびＳｂのアルコキシドと３価の金属の塩またはアルコ
キシドを添加して重合して作製する。次にこのＰＺＴ溶
液を下部電極６aに塗布して乾燥させ，基板を水蒸気と
酸素（または空気）との混合気体中で５００〜８００℃
に加熱して熱分解するとともに結晶化させて焦電センサ
とする。In the above, the pyroelectric sensor is formed as follows, for example. First, a PZT solution is prepared.
This PZT solution was prepared by dissolving lead oxide and acetic anhydride in a 2-methoxyethanol solution, adding Zr, Ti, Sn, and Sb alkoxides and a salt or alkoxide of a trivalent metal to the solution, and polymerizing. Create. Then dried and coating the PZT solution to the lower electrode 6 a, 500 to 800 ° C. The substrate in a mixed gas of steam and oxygen (or air)
It is pyrolyzed by heating it to a pyroelectric sensor.
【０００９】１５はダイアフラム３以外の部分の基板１
上に形成された信号処理部であり，この信号処理部１５
には例えばＦＥＴ等により第１，第２の増幅装置が形成
されており，これらの増幅装置には上部，下部取り出し
電極からのリード線（図示せず）が接続されている。Reference numeral 15 is a substrate 1 other than the diaphragm 3.
This is the signal processing unit formed above, and this signal processing unit 15
First and second amplification devices are formed by, for example, FETs, and lead wires (not shown) from the upper and lower extraction electrodes are connected to these amplification devices.
【００１０】２０は第１基板と同程度の大きさに形成さ
れた例えばシリコンからなる第２基板であり，枠２０a
の中央部に４本の梁２１1〜２１4に支持されたチョッパ
ー部２２が形成されている。このチョッパー部２２の大
きさは第１基板のセンサアレイ部分４とほぼ同一であ
り，アレイ状に形成された焦電センサ４aの長さと幅の
形状に合わせて一つ置きに検出素子を遮蔽するように形
成されている。なお，この第２基板２のチョッパー部
（両持ち梁）２２には赤外線の透過を防止するために表
面に金薄膜が形成されている。[0010] 20 is a second substrate made of, for example, silicon formed to a size comparable to the first substrate, the frame 20 a
A chopper portion 22 supported by the four beams 21 1 to 21 4 is formed in the central portion of the. The size of the chopper portion 22 is almost the same as that of the sensor array portion 4 of the first substrate, and every other detector element is shielded according to the shape of the length and width of the pyroelectric sensor 4 a formed in an array. Is formed. In addition, a gold thin film is formed on the surface of the chopper portion (double-supported beam) 22 of the second substrate 2 in order to prevent transmission of infrared rays.
【００１１】２３は静電駆動部であり,チョッパー部２
２からチョッパーの長手方向に対して直角方向に櫛歯状
に複数本の片持ち梁が形成され，枠２０a側からはその
片持ち梁に交互に入り込む様に同様の櫛歯状片持ち梁が
形成されている。そして，この櫛歯状片持ち梁の対向す
る側面に電極を設け交互に電圧を印加すればこの駆動部
２３は矢印で示す方向に変位する。この駆動距離の調整
はセンサアレイのピッチに合わせて印加電圧を調整して
決定する。Reference numeral 23 denotes an electrostatic drive unit, which is a chopper unit 2.
A plurality of cantilever beams are formed in a comb shape in a direction perpendicular to the longitudinal direction of the chopper from 2, and the same comb tooth-shaped cantilever beams are formed so as to alternately enter the cantilever beams from the frame 20 a side. Are formed. Then, if electrodes are provided on the opposite side surfaces of the comb-shaped cantilever, and a voltage is applied alternately, the drive unit 23 is displaced in the direction indicated by the arrow. The adjustment of the driving distance is determined by adjusting the applied voltage according to the pitch of the sensor array.
【００１２】ここでセンサアレイとチョッパーの関係を
図３（ａ），（ｂ）に示す要部断面図を用いて説明す
る。なお，これらの図における符号は図１と同一であ
る。図３（ａ）はチョッパーが駆動していない状態であ
り，孔１０ａはセンサ４ａ 1，４ａ3の奇数番目に対応し
ている。次にチョッパーが駆動されるとチョッパーは矢
印方向に移動して孔１０ａは偶数番目のセンサ４ａ2，
４ａ4に対応する。Here, the relationship between the sensor array and the chopper is
This will be described with reference to the sectional views of the main parts shown in FIGS. 3 (a) and 3 (b).
It The reference numerals in these figures are the same as those in FIG.
It FIG. 3A shows a state where the chopper is not driven.
The hole 10a is the sensor 4a 1, 4a3Corresponding to the odd number of
ing. The next time the chopper is driven, the chopper will show an arrow.
The hole 10a is moved in the direction of the mark and the holes 10a are even-numbered sensors 4a.2，
4aFourCorresponding to.
【００１３】なお，図では４本のセンサを示しているが
センサの数は任意に増減可能である。また，第１，第２
基板の形状も本実施例に限ることなく任意であり，セン
サアレイ４およびチョッパー部を保持する梁は図示では
４本としているが２本の梁で支持してもよい。そして，
これら第１，第２基板の加工はフォトリソグラフィとエ
ッチングの技術を用いた一般的な半導体技術により行う
ことができる。また，第２基板の材質としてはシリコン
に限ることなく，水晶などの圧電体を用い圧電駆動する
方式であってもい。Although four sensors are shown in the figure, the number of sensors can be arbitrarily increased or decreased. Also, the first and second
The shape of the substrate is not limited to that of this embodiment, and the number of beams holding the sensor array 4 and the chopper portion is four in the figure, but two beams may be used for supporting. And
The processing of these first and second substrates can be performed by a general semiconductor technique using photolithography and etching techniques. Further, the material of the second substrate is not limited to silicon, and a piezoelectric driving method using a piezoelectric body such as crystal may be used.
【００１４】図４はこれら第１，第２基板を適当な厚さ
のスペーサを介して固定し，容器３０に密封した状態を
示す断面図である。密封に際しては埃やガス，温度変化
の影響を防止するために，ペルチェ調温器３１を組み込
むとともに不活性ガスを封入し，さらに．不要な光を遮
断するために赤外線透過フィルタ３２を介して光が入射
するように構成する。FIG. 4 is a sectional view showing a state in which these first and second substrates are fixed via a spacer having an appropriate thickness and sealed in a container 30. At the time of sealing, in order to prevent the influence of dust, gas, and temperature change, a Peltier temperature controller 31 was incorporated and an inert gas was sealed in. In order to block unnecessary light, light is incident through the infrared transmission filter 32.
【００１５】図５は上記の焦電センサに赤外線を照射し
て発生した電気信号の処理状態を示す回路図である。チ
ョッパーを静電駆動して焦電センサへの入射光を断続さ
せると，赤外線の吸収により温度変化が起こって焦電効
果による表面電荷化が生じる。この電気信号を２つのＦ
ＥＴによってインピーダンス変換し，逆相の交流信号の
一方を反転させて加算する。この回路によれば２倍の出
力電圧を得ることができる。FIG. 5 is a circuit diagram showing a processing state of an electric signal generated by irradiating the pyroelectric sensor with infrared rays. When the chopper is electrostatically driven to interrupt the incident light to the pyroelectric sensor, infrared rays are absorbed to change the temperature, which causes surface charge due to the pyroelectric effect. This electric signal is
The impedance is converted by ET, and one of the AC signals of opposite phase is inverted and added. According to this circuit, a double output voltage can be obtained.
【００１６】[0016]
【発明の効果】以上，詳細に説明したように，本発明に
よれば，焦電素子をシリコンダイアフラム上に薄膜とし
て形成し，さらに断熱層を設けているので，熱容量を極
めて小さくすることが可能であり，その結果，応答速度
および感度の高い赤外線センサを実現することができ
る。As described above in detail, according to the present invention, since the pyroelectric element is formed as a thin film on the silicon diaphragm and the heat insulating layer is further provided, the heat capacity can be made extremely small. As a result, an infrared sensor with high response speed and high sensitivity can be realized.
【図１】本発明の一実施例を示す構成斜視図である。FIG. 1 is a configuration perspective view showing an embodiment of the present invention.
【図２】図１（ａ）のＡーＡ断面図である。FIG. 2 is a sectional view taken along line AA of FIG.
【図３】センサアレイとチョッパーの関係を示す図であ
る。FIG. 3 is a diagram showing a relationship between a sensor array and a chopper.
【図４】センサを容器に密封した状態を示す断面図であ
る。FIG. 4 is a cross-sectional view showing a state where the sensor is sealed in a container.
【図５】電気信号の処理状態を示す回路図である。FIG. 5 is a circuit diagram showing a processing state of an electric signal.
１ 第１基板 ２，１０，１０a 孔 ３ ダイアフラム ４ センサアレイ ４ａ 焦電センサ ４1〜４4，２１1〜２１4 梁 ５ 絶縁膜 ６ 断熱層 ６ａ 下部電極 ７ 焦電膜 ８ 上部電極 ９ 光吸収膜 １１ 取り出し電極 １５ 信号処理部 ２０ 第２基板 ２０ａ 枠 ２２ チョッパー部 ２３ 静電駆動部1 1st substrate 2, 10, 10 a hole 3 Diaphragm 4 Sensor Array 4a Pyroelectric Sensor 4 1 to 4 4 , 21 1 to 21 4 Beam 5 Insulating Film 6 Insulating Layer 6a Lower Electrode 7 Pyroelectric Film 8 Upper Electrode 9 Light Absorbing Film 11 Extraction Electrode 15 Signal Processing Unit 20 Second Substrate 20a frame 22 chopper section 23 electrostatic drive section
Claims (1)
イアフラムと，このダイアフラム上に形成された絶縁膜
と，前記ダイアフラムと絶縁膜間に形成された断熱層
と，前記絶縁膜上に下部電極，焦電膜，上部電極および
光吸収膜が順次積層され，前記絶縁膜を含む前記積層さ
れた層が複数の長方形の孔により，アレイ状に分離され
た焦電センサを有する第１基板と，少なくとも２本の梁
に支持され前記第１基板の複数の焦電センサの形状とほ
ぼ同一形状に形成された複数のチョッパーと，これらの
チョッパーを面方向に駆動する駆動手段からなる第２基
板とからなり，前記第１基板上に第２基板を配設し，前
記焦電センサ上で前記チョッパーを面方向に往復駆動し
て前記焦電センサに入射する赤外線をチョッピングする
ように構成したことを特徴とする赤外線センサ。1. A diaphragm supported by at least two beams, an insulating film formed on the diaphragm, a heat insulating layer formed between the diaphragm and the insulating film, and a lower electrode on the insulating film. A pyroelectric film, an upper electrode, and a light absorption film are sequentially laminated, and the laminated substrate including the insulating film is divided into an array by a plurality of rectangular holes, and a first substrate having a pyroelectric sensor, and at least From a plurality of choppers supported by two beams and formed in substantially the same shape as the plurality of pyroelectric sensors of the first substrate, and a second substrate composed of driving means for driving these choppers in a plane direction. The second substrate is disposed on the first substrate, and the chopper is reciprocally driven in the surface direction on the pyroelectric sensor to chop the infrared rays incident on the pyroelectric sensor. Characteristic infrared sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4002436A JPH05187917A (en) | 1992-01-09 | 1992-01-09 | Infrared sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4002436A JPH05187917A (en) | 1992-01-09 | 1992-01-09 | Infrared sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05187917A true JPH05187917A (en) | 1993-07-27 |
Family
ID=11529222
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4002436A Pending JPH05187917A (en) | 1992-01-09 | 1992-01-09 | Infrared sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05187917A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5583058A (en) * | 1992-09-17 | 1996-12-10 | Mitsubishi Denki Kabushiki Kaisha | Infrared detection element array and method for fabricating the same |
| JPWO2010073288A1 (en) * | 2008-12-22 | 2012-05-31 | パイオニア株式会社 | Infrared sensor and method of manufacturing infrared sensor |
| US8916824B2 (en) | 2011-10-31 | 2014-12-23 | Seiko Epson Corporation | Pyroelectric light detector, pyroelectric light detecting device, and electronic device |
-
1992
- 1992-01-09 JP JP4002436A patent/JPH05187917A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5583058A (en) * | 1992-09-17 | 1996-12-10 | Mitsubishi Denki Kabushiki Kaisha | Infrared detection element array and method for fabricating the same |
| JPWO2010073288A1 (en) * | 2008-12-22 | 2012-05-31 | パイオニア株式会社 | Infrared sensor and method of manufacturing infrared sensor |
| US8916824B2 (en) | 2011-10-31 | 2014-12-23 | Seiko Epson Corporation | Pyroelectric light detector, pyroelectric light detecting device, and electronic device |
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