JPH0744285B2 - Method for forming anodized film - Google Patents
Method for forming anodized filmInfo
- Publication number
- JPH0744285B2 JPH0744285B2 JP63155388A JP15538888A JPH0744285B2 JP H0744285 B2 JPH0744285 B2 JP H0744285B2 JP 63155388 A JP63155388 A JP 63155388A JP 15538888 A JP15538888 A JP 15538888A JP H0744285 B2 JPH0744285 B2 JP H0744285B2
- Authority
- JP
- Japan
- Prior art keywords
- solution
- hgcdte
- oxide film
- value
- anodic oxide
- 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
Landscapes
- Formation Of Insulating Films (AREA)
- Light Receiving Elements (AREA)
Description
【発明の詳細な説明】 〔概 要〕 赤外線検知用HgCdTe素子の表面保護膜形成方法に関し、 低周波雑音を減少させることを目的とし、 HgCdTe検知素子を表面処理する陽極酸化工程において、
電離性イオンが含まれたpH＝７〜９からなる中性ないし
弱アルカリ性溶液を調整し、該溶液に前記HgCdTe検知素
子を浸漬して陽極酸化膜を形成する工程が含まれてなる
構成とする。DETAILED DESCRIPTION OF THE INVENTION [Summary] A method for forming a surface protective film for an infrared ray detection HgCdTe element, which aims to reduce low frequency noise, in an anodizing step of surface-treating an HgCdTe element,
It is configured to include a step of preparing a neutral to weakly alkaline solution containing ionizing ions of pH = 7 to 9 and immersing the HgCdTe sensing element in the solution to form an anodic oxide film. .
本発明は赤外線検知用HgCdTe素子の表面保護膜形成方法
に関する。The present invention relates to a method for forming a surface protective film on a HgCdTe element for infrared detection.
赤外線撮像装置のセンサとしてHgCdTe素子が用いられて
おり、その素子特性を安定にするために素子面に陽極酸
化膜を被覆しているが、本発明はその陽極酸化膜の形成
法に関している。An HgCdTe element is used as a sensor of an infrared imaging device, and the element surface is covered with an anodic oxide film in order to stabilize the element characteristics. The present invention relates to a method for forming the anodic oxide film.
第３図は光電導型赤外線検知素子としてのHgCdTe（水銀
カドミウムテルル）素子を示しており、第３図（ａ）は
平面図，第３図（ｂ）は同図（ａ）のAA断面図である。
図中の１はHgCdTe基板（膜厚10μｍ程度）,2は電極,3は
陽極酸化膜（膜厚数百Å）であつて、この陽極酸化膜３
が表面を保護するためのカバー絶縁膜である。FIG. 3 shows an HgCdTe (mercury cadmium tellurium) element as a photoconductive infrared detector element. FIG. 3 (a) is a plan view and FIG. 3 (b) is a sectional view taken along the line AA of FIG. 3 (a). Is.
In the figure, 1 is an HgCdTe substrate (film thickness is about 10 μm), 2 is an electrode, 3 is an anodic oxide film (film thickness is several hundred Å).
Is a cover insulating film for protecting the surface.
なお、赤外線撮像装置はこのような赤外線検知素子を並
列またはマトリックス状に複数個配列したもので、第３
図はその１素子を図示したものである。また、光電導型
検知素子とは赤外線（矢印で示す）を関知するとフォト
ン（光子）が発生し、そのため両電極間の抵抗が低下す
る原理に基づいたセンサ素子である。It should be noted that the infrared imaging device has a plurality of such infrared detecting elements arranged in parallel or in a matrix.
The figure shows one of the elements. Further, the photoconductive detection element is a sensor element based on the principle that photon (photon) is generated when infrared rays (indicated by an arrow) are detected, and thus the resistance between both electrodes is reduced.
さて、上記のカバー絶縁膜としてはHgCdTe基板を高温酸
化して酸化膜を形成することが考えられるが、加熱する
とHgが蒸発するなどして、HgCdTe基板の組成変化が起こ
るために、常温での陽極酸化法によつて陽極酸化膜３を
形成する方法が採られているものである。第４図はその
陽極酸化をするための陽極酸化装置の概要図を示し、図
中の11は処理容器,12はHgCdTe素子（陽極）,13は陽極に
対向して配置した陰極（化学的に安定な導体，例えば炭
素や白金材料）で、この両電極12,13の間に電源14を接
続して一定電流を流し、HgCdTe素子の露出面に陽極酸化
膜を形成するが、その時、陽極酸化溶液は例えば、苛性
カリ（KOH）をエチレングリコール900ml,水100mlに溶解
して、KOH0.1モルとしたもの（液Ｉとする）を用いてな
る。なお、この溶液のpH値は12.5程度で強アルカリ性溶
液である。Now, as the cover insulating film, it is possible to oxidize the HgCdTe substrate at high temperature to form an oxide film, but when Hg evaporates when heated, the composition of the HgCdTe substrate changes, so The method of forming the anodic oxide film 3 by the anodic oxidation method is adopted. FIG. 4 shows a schematic diagram of the anodizing apparatus for performing the anodization. In the figure, 11 is a processing container, 12 is a HgCdTe element (anode), and 13 is a cathode (chemically A stable conductor, such as carbon or platinum material, is used to connect a power supply 14 between the electrodes 12 and 13 to allow a constant current to flow and form an anodic oxide film on the exposed surface of the HgCdTe element. The solution is, for example, a solution obtained by dissolving caustic potash (KOH) in 900 ml of ethylene glycol and 100 ml of water to make 0.1 mol of KOH (referred to as liquid I). The pH value of this solution is about 12.5 and it is a strong alkaline solution.
ところが、上記した溶液のような強アルカリ性溶液を用
いて陽極酸化膜を形成すると、低周波雑音が大きくなる
と云う欠点があり、本発明はその低周波雑音を減少させ
ることを目的とした陽極酸化膜の形成方法を提案するも
のである。However, when an anodic oxide film is formed using a strong alkaline solution such as the above-mentioned solution, there is a drawback that low frequency noise becomes large, and the present invention has an anodized film for the purpose of reducing the low frequency noise. Is proposed.
その目的は、電離性イオンが含まれたpH＝７〜９からな
る中性ないし弱アルカリ性溶液を調整し、その溶液にHg
CdTe検知素子を浸漬して陽極酸化膜を形成する工程が含
まれる形成方法によつて達成される。The purpose is to prepare a neutral to weakly alkaline solution of pH = 7-9 containing ionizing ions, and add Hg to the solution.
It is achieved by a forming method including a step of immersing a CdTe sensing element to form an anodized film.
即ち、本発明はpH値を調整してpH＝７〜９とし、これを
陽極酸化溶液にして陽極酸化膜を形成する。そうする
と、低周波雑音を減少させる効果がある。That is, in the present invention, the pH value is adjusted to pH = 7-9, and this is used as an anodizing solution to form an anodized film. This has the effect of reducing low frequency noise.
以下、図面を参照して実施例により詳細に説明する。 Hereinafter, embodiments will be described in detail with reference to the drawings.
例えば、陽極酸化溶液としてKOHおよび硼酸（H3BO3）を
エチレングリコール900ml,水100mlに溶解して、KOH0.1
モル,H3BO30.09モルにした溶液（液IIとする）を用いる
が、その溶液のpH値は8.5程度になる。そうして、その
ような溶液を使用して陽極酸化膜を生成し、そのHgCdTe
素子の周波数（HZ）と雑音電圧（相対値）との関係を調
べた結果のデータを第１図に示している。実線が本発明
にかかる溶液（液II）で陽極酸化膜を形成したデータ，
破線は従来の溶液（液Ｉ）で陽極酸化膜を形成したデー
タであり、このデータより本発明にかかる溶液（液II）
を用いれば、1KHZ以下の雑音が減少するのが明らかであ
る。且つ、低周波雑音の大きさを評価するパラメータと
してコーナー周波数があり、これはキャリアの生成−再
結合雑音よりも3dB高くなつた周波数を意味するが、第
１図にそれぞれ●点でそのコーナー周波数を示してい
る。このコーナー周波数は液Ｉでは約1KHZのコーナー周
波数であるが、液IIでは約200HZ程度のコーナー周波数
に低下していることが判る。For example, KOH and boric acid (H 3 BO 3 ) as an anodizing solution are dissolved in 900 ml of ethylene glycol and 100 ml of water, and KOH 0.1
A solution containing 0.09 mol of H 3 BO 3 and H 2 BO 3 (solution II) is used, and the pH value of the solution is about 8.5. Then, using such a solution, an anodic oxide film is produced and its HgCdTe
FIG. 1 shows data obtained as a result of examining the relationship between the frequency (HZ) of the device and the noise voltage (relative value). The solid line is the data of forming an anodized film with the solution according to the present invention (Liquid II),
The broken line is the data obtained by forming the anodic oxide film with the conventional solution (Liquid I). From this data, the solution (Liquid II) according to the present invention can be obtained.
It is clear that the noise below 1KHZ is reduced by using. Moreover, there is a corner frequency as a parameter for evaluating the magnitude of low frequency noise, which means a frequency that is 3 dB higher than the carrier generation-recombination noise. Is shown. It can be seen that this corner frequency is about 1 KHZ for liquid I, but has decreased to about 200 HZ for liquid II.
次に、第２図はH3BO3の混合量を変え、溶液のpH値を変
化させて得たpH値とコーナー周波数との関係を示してい
る。これより、pH値が９以上になればコーナー周波数が
1KHZ以上と高くなることが明白である。Next, FIG. 2 shows the relationship between the pH value and the corner frequency obtained by changing the pH value of the solution by changing the mixing amount of H 3 BO 3 . From this, if the pH value is 9 or more, the corner frequency will be
It is clear that it will be higher than 1KHZ.
これらの結果より、本発明はpH＝７〜９の溶液を用いて
陽極酸化すれば低周波雑音の減少したHgCdTe検知素子を
得ることが明らかで、それを提案するものである。しか
し、上記実施例のように、KOHにH3BO3を添加してpH値を
調整するだけでなく、他の酸性物質を添加してpH値を調
整しても良いし、又、他の溶液、例えば重炭酸ソーダ
（NaHCO3）やH2O2（過酸化水素）などの溶液のみを用い
てpH値を調整し、それによつて陽極酸化しても同様の効
果があり、要するに電離性イオンを含むpH＝７〜９の溶
液で陽極酸化すれば良い。なお、pH値を変えても処理時
間は殆ど変らず、従来と同程度の処理時間で陽極酸化膜
が得られることを付記しておく。From these results, it is clear that the present invention can obtain a HgCdTe detection element with reduced low-frequency noise by anodizing using a solution of pH = 7-9, and proposes it. However, as in the above embodiment, not only by adjusting the pH value by adding H 3 BO 3 in KOH, it may be to adjust the pH value by addition of other acidic substances, also other The pH value is adjusted using only a solution, such as sodium bicarbonate (NaHCO 3 ) or H 2 O 2 (hydrogen peroxide), and the same effect can be obtained by anodizing the pH value. Anodization may be performed with a solution containing pH = 7 to 9. It should be noted that the treatment time hardly changes even if the pH value is changed, and the anodic oxide film can be obtained in the same treatment time as the conventional one.
以上の説明から明らかなように、本発明によれば低周波
雑音の減少したHgCdTe素子が得られ、その素子特性が改
善されて赤外線検知器の性能向上に顕著に効果があるも
のである。As is clear from the above description, according to the present invention, an HgCdTe device with reduced low frequency noise can be obtained, and the device characteristics thereof are improved, which is remarkably effective in improving the performance of the infrared detector.
第１図はHgCdTe素子の周波数と雑音電圧との関係を示す
図、 第２図はpH値とコーナー周波数との関係を示す図、 第３図はHgCdTe素子を示す図、 第４図は陽極酸化装置の概要図である。 図において、 １はHgCdTe基板、２は電極、 ３は陽極酸化膜、 11は処理容器、12はHgCdTe素子（陽極）、 13は陰極、14は電源 を示している。Fig. 1 shows the relationship between frequency and noise voltage of HgCdTe element, Fig. 2 shows the relationship between pH value and corner frequency, Fig. 3 shows HgCdTe element, and Fig. 4 shows anodic oxidation. It is a schematic diagram of an apparatus. In the figure, 1 is a HgCdTe substrate, 2 is an electrode, 3 is an anodic oxide film, 11 is a processing container, 12 is a HgCdTe element (anode), 13 is a cathode, and 14 is a power supply.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 前川 通 神奈川県川崎市中原区上小田中1015番地 富士通株式会社内 (72)発明者 瀧川 宏 神奈川県川崎市中原区上小田中1015番地 富士通株式会社内 (56)参考文献 特開 昭60−98685（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Maedagawa 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Hiroshi Takigawa 1015, Kamedotachu, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited ( 56) References JP-A-60-98685 (JP, A)
Claims (1)
程において、 電離性イオンが含まれたpH＝７〜９からなる中性ないし
弱アルカリ性溶液を調整し、該溶液に前記HgCdTe検知素
子を浸漬して陽極酸化膜を形成する工程が含まれてなる
ことを特徴とする陽極酸化膜の形成方法。1. An anodizing step for surface-treating a HgCdTe detection element, a neutral to weakly alkaline solution containing ionizing ions of pH = 7-9 is prepared, and the HgCdTe detection element is dipped in the solution. And a step of forming an anodic oxide film is included.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63155388A JPH0744285B2 (en) | 1988-06-22 | 1988-06-22 | Method for forming anodized film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63155388A JPH0744285B2 (en) | 1988-06-22 | 1988-06-22 | Method for forming anodized film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01321639A JPH01321639A (en) | 1989-12-27 |
| JPH0744285B2 true JPH0744285B2 (en) | 1995-05-15 |
Family
ID=15604863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63155388A Expired - Fee Related JPH0744285B2 (en) | 1988-06-22 | 1988-06-22 | Method for forming anodized film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0744285B2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2553580B1 (en) * | 1983-10-13 | 1986-09-12 | Telecommunications Sa | PROCESS FOR PASSIVATING HG CD TE PHOTOCONDUCTOR SENSORS |
-
1988
- 1988-06-22 JP JP63155388A patent/JPH0744285B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01321639A (en) | 1989-12-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS5529940A (en) | Method and apparatus for determining activity of microorganism | |
| US5200053A (en) | Reference electrode | |
| US2708242A (en) | Radiation dosimeter | |
| US3179581A (en) | Electrochemical dosimeter | |
| JPS5610219A (en) | Ultraviolet integral detecting element and ultraviolet integral detector | |
| JPH0744285B2 (en) | Method for forming anodized film | |
| US6087651A (en) | Highly sensitive light reception element | |
| Minc et al. | Properties of the electrical double layer in solutions of electrolytes in some organic solvents | |
| US3861031A (en) | Method of making a moisture-sensitive element | |
| US4118546A (en) | Triple electrode photogalvanic cell with energy storage capability | |
| Anastopoulos et al. | Adsorption of Tri (n) octylphosphine oxide at the mercury electrode from methanol and water-methanolic mixtures | |
| CA1080372A (en) | Cadmium telluride nuclear detector | |
| Strehblow et al. | Electrochemical surface reactions on PbTe | |
| JPH0697258B2 (en) | Method for detecting specific gravity of electrolyte in lead acid battery | |
| GB2237291A (en) | Method of bridging gaps in a substrate by electrodeposited film, for use in gas sensor manufacture | |
| SU468143A1 (en) | The method of visualization of current density distribution | |
| US4122345A (en) | Semiconductor detector for detecting ionizing radiation | |
| JPS5572853A (en) | Determining method for ammonia by microorganism electrode | |
| Sane et al. | Simultaeous estimation of copper (II) and mercury (I) ion by electrodes modified with ion exchanger resin | |
| JP2772833B2 (en) | Method for manufacturing ion sensor, method for manufacturing sensor plate, and method for storing these | |
| JPS5789265A (en) | Photo electromotive element | |
| US3692659A (en) | Electrolytic reversible color display device | |
| US3654117A (en) | Electrode stencil for anodic printing | |
| JPS5654344A (en) | Ozone electrode | |
| Šušić et al. | Electrochemical behaviour of the solid electrolyte Ag6I4WO4 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |