JPH0821536B2 - Exposure intensity measurement method - Google Patents
Exposure intensity measurement methodInfo
- Publication number
- JPH0821536B2 JPH0821536B2 JP63228389A JP22838988A JPH0821536B2 JP H0821536 B2 JPH0821536 B2 JP H0821536B2 JP 63228389 A JP63228389 A JP 63228389A JP 22838988 A JP22838988 A JP 22838988A JP H0821536 B2 JPH0821536 B2 JP H0821536B2
- Authority
- JP
- Japan
- Prior art keywords
- exposure
- intensity
- filter
- resist
- filters
- 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
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Measurement Of Radiation (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は,半導体製造工程で用いる露光装置等に関
し,特にウェハ上に塗布されたレジストにマスクパター
ンを露光転写する露光装置における転写露光用光線の強
度測定方法および装置に関するものである。TECHNICAL FIELD The present invention relates to an exposure apparatus and the like used in a semiconductor manufacturing process, and particularly to a light beam for transfer exposure in an exposure apparatus for exposing and transferring a mask pattern onto a resist coated on a wafer. The present invention relates to an intensity measuring method and device.
近年の集積回路の微細化に伴い現像後のレジスト線幅
の均一性が一層要求されるようになってきた。レジスト
線幅の均一性を達成するにはマスク線幅の均一性や現像
条件の安定性はもちろんのこと露光量の一様性が重要と
なってくる。露光領域内の各位置で単位時間当たりのレ
ジストの露光量を測定できれば,各位置で露光量に見合
った時間露光することにより領域内で一定の露光量を得
ることができる。従って,ウェハ面上の露光強度測定は
十分な信頼性を必要とし,露光強度検出が重要な問題と
なってくる。With the miniaturization of integrated circuits in recent years, there has been an increasing demand for uniformity of resist line width after development. In order to achieve the uniformity of the resist line width, not only the uniformity of the mask line width and the stability of the developing conditions but also the uniformity of the exposure amount are important. If the exposure amount of the resist per unit time can be measured at each position in the exposure area, a constant exposure amount can be obtained in the area by performing the exposure at each position for a time corresponding to the exposure amount. Therefore, the exposure intensity measurement on the wafer surface requires sufficient reliability, and the exposure intensity detection becomes an important issue.
一般にレジストと検出器の感度は一致しないが,ウェ
ハ面内で相対的な分光強度が同じ場合,例えば光露光や
X線管球等による露光では,各点での安定した検出器の
出力が得られれば,それに応じた時間だけ露光すること
により均一な露光量を得ることができる。Generally, the resist and the detector do not have the same sensitivity, but when the relative spectral intensities are the same in the wafer surface, for example, in light exposure or exposure with an X-ray tube, a stable detector output can be obtained at each point. If so, it is possible to obtain a uniform exposure amount by performing exposure for a corresponding time.
しかしながら,近年注目を浴びているシンクロトロン
放射光をX線ミラーによって反射させる露光方法では,
一般には露光位置によってX線の絶対強度はもちろん波
長分布に大きな差があり,検出器による強度測定は困難
であった。例えばミラー揺動法や固定ミラー等によって
放射光を拡大する場合,露光位置による波長分布の差異
を無視してX線強度測定を行い,検出器の出力に基づい
て各露光位置における露光時間を決定すると,ウェハ面
内で±10%以上の露光むらが生じるおそれがあった。こ
れは検出器とレジストの感じる波長が異なるためであ
る。そこで従来このような場合,レジストを露光してそ
の結果から各点でのX線強度を測定していた。例えばレ
ジストを露光,現像してX線強度を測定した例は,特開
昭59−69927号公報に開示されまた1988春の応用物理学
会(28p−N−18)等で報告されている。しかしなが
ら,レジスト露光によるX線強度測定には次のような欠
点があった。However, in the exposure method in which the synchrotron radiation, which has been attracting attention in recent years, is reflected by an X-ray mirror,
Generally, there is a large difference in the wavelength distribution as well as the absolute intensity of X-rays depending on the exposure position, and it is difficult to measure the intensity with a detector. For example, when the emitted light is expanded by a mirror swing method or a fixed mirror, X-ray intensity measurement is performed ignoring the difference in wavelength distribution depending on the exposure position, and the exposure time at each exposure position is determined based on the output of the detector. Then, exposure unevenness of ± 10% or more may occur on the wafer surface. This is because the detector and the resist sense different wavelengths. Therefore, conventionally, in such a case, the resist is exposed and the X-ray intensity at each point is measured from the result. For example, an example of exposing and developing a resist to measure the X-ray intensity is disclosed in JP-A-59-69927 and is reported in the Applied Physics Society of Japan (28p-N-18), etc. However, the X-ray intensity measurement by resist exposure has the following drawbacks.
a.レジストの現像条件や再現性がそのまま露光時間の誤
差となる等精度上問題があった。a. There was a problem in accuracy such that the developing conditions and reproducibility of the resist would directly cause an error in the exposure time.
b.測定の精度を上げるためには,多くの実験を行わなく
てはならず,多くの時間を要した。b. In order to improve the accuracy of the measurement, many experiments had to be conducted and it took a lot of time.
c.注入電子の軌道変化やミラー,Be(ベリリウム)窓の
汚染によって露光波長が変化した場合その度毎に試し露
光を行う必要があった。c. When the exposure wavelength changed due to the change of the orbit of the injected electrons and the contamination of the mirror and Be (beryllium) window, it was necessary to perform the trial exposure each time.
本発明は上記従来技術の欠点に鑑みなされたものであ
って,高精度でかつ短時間でウェハ面上の露光量分布を
測定可能な露光強度測定方法の提供を目的とする。The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object thereof is to provide an exposure intensity measuring method capable of measuring the exposure dose distribution on the wafer surface with high accuracy and in a short time.
前記目的を達成するため,本発明では,レジストを塗
布したウェハ上にマスクのパターンを露光転写する露光
装置における露光領域での露光用光線強度分布測定方法
であって,露光領域の各点において,マスク基板と同一
材料からなる第1のフィルターを透過する光線の強度
と,前記マスク基板と同一材料の基板上にレジストを塗
布した第2のフィルターを透過する光線の強度との差を
検出し,該検出結果に基づいて前記露光領域各点での光
線強度を求めている。In order to achieve the above-mentioned object, the present invention provides a method of measuring a light intensity distribution for exposure in an exposure area in an exposure apparatus for exposing and transferring a pattern of a mask onto a wafer coated with a resist, wherein Detecting a difference between the intensity of a light beam transmitted through a first filter made of the same material as the mask substrate and the intensity of a light beam transmitted through a second filter coated with a resist on the substrate made of the same material as the mask substrate; The light intensity at each point of the exposure area is obtained based on the detection result.
一般に同種のレジストにおいて,感光度は露光に寄与
する光線の吸収量に比例すると考えられている。特にX
線領域内での露光では,吸収されたX線が二次電子を放
出しそれらがレジストを感光させると考えられるため,
近似的にX線の吸収量は感光度に比例するとしてよい。In the same type of resist, it is generally considered that the photosensitivity is proportional to the amount of absorption of light rays that contribute to exposure. Especially X
In the exposure in the line region, it is considered that the absorbed X-rays emit secondary electrons and they expose the resist,
The amount of X-ray absorption may be approximately proportional to the photosensitivity.
そこで本発明の基本概念は,露光位置の各点でレジス
トの吸収量を測定し,ウェハ面上の各点における露光強
度を求めるものである。Therefore, the basic concept of the present invention is to measure the amount of absorption of the resist at each point of the exposure position and obtain the exposure intensity at each point on the wafer surface.
以下図面を参照して本発明の実施例について説明す
る。なお,本発明はX線領域の露光に限るものではない
が,以下の説明ではX線露光について述べる。Embodiments of the present invention will be described below with reference to the drawings. Although the present invention is not limited to exposure in the X-ray region, X-ray exposure will be described below.
第1図は本発明方法を実施するための装置の一例の斜
視図であり,第2図は第1図のA−A断面図,第3図は
本発明に係わる露光装置の概念図である。第4図はミラ
ー揺動におけるX線の分光強度のグラフ,第5図は従来
技術による露光むらを示す図,第6図は本発明による露
光むらを示す図である。第7図および第8図は各々本発
明の別の実施例を示す図,第9図は第8図のA−A断面
図である。FIG. 1 is a perspective view of an example of an apparatus for carrying out the method of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a conceptual view of an exposure apparatus according to the present invention. . FIG. 4 is a graph of the X-ray spectral intensity in the mirror swing, FIG. 5 is a diagram showing exposure unevenness according to the prior art, and FIG. 6 is a diagram showing exposure unevenness according to the present invention. 7 and 8 are views showing another embodiment of the present invention, and FIG. 9 is a sectional view taken along line AA of FIG.
図において,1は露光用のマスク基板と同じ材料の薄膜
6からなる第1のフィルター,2は露光用のマスク基板と
同じ材料の薄膜6上にレジスト7を塗布した第2のフィ
ルター,3は第1および第2のフィルター1,2を支持する
フィルターホルダ,4はX線強度検出器である。X線強度
検出器4は図示しないアンプに接続され出力が読み取ら
れる。5はホルダ駆動部であり外部からの信号によりフ
ィルター3を回転させることができる。8はX線,9はSR
リング,10はX線ミラー,11はステージ,12はX線マスク,
13はハイパスフィルターなどの交流成分を検出する回路
である。In the figure, 1 is a first filter made of a thin film 6 made of the same material as the exposure mask substrate, 2 is a second filter made by applying a resist 7 on the thin film 6 made of the same material as the exposure mask substrate, and 3 is A filter holder 4 supporting the first and second filters 1 and 2 is an X-ray intensity detector. The X-ray intensity detector 4 is connected to an amplifier (not shown) and its output is read. Reference numeral 5 denotes a holder driving unit, which can rotate the filter 3 by a signal from the outside. 8 is X-ray, 9 is SR
Ring, 10 is an X-ray mirror, 11 is a stage, 12 is an X-ray mask,
Reference numeral 13 is a circuit for detecting an AC component such as a high pass filter.
以下本発明の理論について説明を加える。 The theory of the present invention will be described below.
露光位置yにおける露光後のレジスト吸収量De(y)
は,単位時間当たりのレジスト吸収量D(y)と各点に
おける露光時間Te(y)によって次式で表せる。Resist absorption amount De (y) after exposure at exposure position y
Can be expressed by the following equation by the resist absorption amount D (y) per unit time and the exposure time Te (y) at each point.
De(y)=D(y)*Te(y) ・・・(1) ここで露光位置yとは任意の露光点の座標を示す。ま
た,Te(y)はX線強度データをI(y)とすると Te(y)=C/I(y) ・・・(2) である。ここでI(y)は各位置yでのX線強度とレジ
ストの分光感度から計算または測定によって求められる
値である。比例定数Cはレジストの感度目標とする露光
現像後のレジスト線幅および露光時のX線強度等によっ
て決められる。従って,レジスト吸収量とX線強度デー
タの比D(y)/I(y)をR(y)で定義し,式2を式
1に代入すると, De(y)=C*D(y)/I(y) =C*R(y) となる。さらに露光むらErr(y)を平均露光量からの
差として定義すると Err(y)=(De(y)−▲▼)/▲▼ =(R(y)−)/ ・・・(3) となる。ここで▲▼と▲▼は,y全域にわたる各
々の平均値とする。以上のことから,露光むらを小さく
するには,レジスト吸収量とX線強度データの比R
(y)を一定にすればよいことが分かる。本発明ではX
線強度データI(y)をレジスト吸収量D(y)に近似
的に比例するようにしてR(y)を一定にしようとする
ものである。De (y) = D (y) * Te (y) (1) Here, the exposure position y indicates the coordinates of an arbitrary exposure point. Further, Te (y) is Te (y) = C / I (y) (2) when X-ray intensity data is I (y). Here, I (y) is a value calculated or measured from the X-ray intensity at each position y and the spectral sensitivity of the resist. The constant of proportionality C is determined by the resist line width after exposure and development, which is the sensitivity target of the resist, and the X-ray intensity during exposure. Therefore, if the ratio D (y) / I (y) between the resist absorption amount and the X-ray intensity data is defined as R (y) and Equation 2 is substituted into Equation 1, De (y) = C * D (y) / I (y) = C * R (y). Further, if the exposure unevenness Err (y) is defined as the difference from the average exposure amount, Err (y) = (De (y) − ▲ ▼) / ▲ ▼ = (R (y) −) / (3) Become. Here, ▲ ▼ and ▲ ▼ are the respective average values over the entire y range. From the above, in order to reduce the exposure unevenness, the ratio R of the resist absorption amount and the X-ray intensity data
It can be seen that it is sufficient to keep (y) constant. In the present invention, X
It is intended to make R (y) constant by making the line intensity data I (y) approximately proportional to the resist absorption amount D (y).
次に本発明の基本概念を簡単に述べる。露光用マスク
基板と同種の材料からなる薄膜およびその上にレジスト
を塗布した薄膜からなる第1および第2の2種類のフィ
ルターを用意し,各フィルターを透過したX線強度の差
を検出することによりレジストのみに吸収されたエネル
ギーを測定し前述のR(y)を位置によらず一定値に近
づけようとするものである。Next, the basic concept of the present invention will be briefly described. To prepare a thin film made of the same type of material as the exposure mask substrate and two types of filters, a first thin film and a thin film coated with a resist, and detect the difference in X-ray intensity transmitted through each filter. Is used to measure the energy absorbed only in the resist, and to make R (y) close to a constant value regardless of the position.
以下ミラー揺動法のX線強度測定に本発明を応用した
例について述べる。ミラー揺動法は,第3図に示すよう
に,X線ミラー10を揺動することによりSRリング9からの
狭い幅のX線ビームを上下に振動させ,露光面積を拡大
するのに有効な手段である。しかしX線ミラーの分光反
射率が,入射X線8の視射角θによって,大きく異なる
ので各露光位置におけるX線の分光強度に大きな差があ
る。例えば視射角θ=8mradおよび16mradにおいてSiCミ
ラーによって反射されたX線の分光強度を第4図に示
す。横軸に波長を,縦軸に単位波長当たりのX線強度を
とる。ここで,露光領域は,視射角と装置の配置により
定まるので,視射角を露光位置と考えてよい。例えばX
線ミラー10とウェハが4m離れているとすると露光領域は
30mm角の場合,θ=8mradを露光領域の上端とすると下
端はθ=15.5mradに対応する。このような系において,
露光用マスクとしてSi3N4(2μm厚),レジストとし
てPMMA(1μm厚)を用いた露光では,従来のようにフ
ィルター無しや第1のフィルター(露光用マスク基板)
を透過したX線をX線強度検出器4で測定した値を各位
置でのX線強度データIとして各位置における露光時間
Teを決定すると,式3から露光むらErrは第5図に示す
ように,±10%の誤差を生じてしまう。An example in which the present invention is applied to X-ray intensity measurement by the mirror swing method will be described below. As shown in FIG. 3, the mirror swing method is effective for swinging the X-ray mirror 10 to vertically swing the narrow X-ray beam from the SR ring 9 and expanding the exposure area. It is a means. However, since the spectral reflectance of the X-ray mirror greatly differs depending on the glancing angle θ of the incident X-ray 8, there is a large difference in the X-ray spectral intensity at each exposure position. For example, FIG. 4 shows the spectral intensities of X-rays reflected by the SiC mirror at glancing angles θ = 8 mrad and 16 mrad. The horizontal axis represents wavelength and the vertical axis represents X-ray intensity per unit wavelength. Here, since the exposure area is determined by the glancing angle and the arrangement of the device, the glancing angle may be considered as the exposure position. For example X
If the line mirror 10 and the wafer are 4 m apart, the exposure area is
In the case of 30 mm square, assuming that θ = 8 mrad is the upper end of the exposure area, the lower end corresponds to θ = 15.5 mrad. In such a system,
In the exposure using Si 3 N 4 (2 μm thickness) as the exposure mask and PMMA (1 μm thickness) as the resist, there is no filter or the first filter (exposure mask substrate) as before.
The exposure time at each position is defined as the X-ray intensity data I at each position based on the value measured by the X-ray intensity detector 4 for the X-rays transmitted through
When Te is determined, the uneven exposure Err from Expression 3 causes an error of ± 10% as shown in FIG.
次に,本発明の基本概念に基づいた測定法について説
明する。まず,第3図のように,X線検出器4が所定の露
光位置にくるようにステージ11を移動して第1のフィル
ター1(Si3N4マスク基板2μm厚)をX線検出器4の
上方にセットした後,X線8がX線検出器4の上方を通過
するようにX線ミラー10を揺動し第1のフィルター1を
通してX線8の強度を測定し,その出力をI1とする。次
に,X線検出器4の上方に第2のフィルター2が位置する
ようにホルダ駆動部5によってフィルターホルダ3を回
転し,第2のフィルター2を通してX線強度を測定す
る。その出力をI2とする。なお,第2のフィルター2
は,Si3N4マスク基板(厚さ2μm程度)上にPMMAレジス
トを厚さ1μm程度に塗布した構造である。このように
して測定したI1,I2の差(=I1−I2)を求め,これをそ
の位置におけるX線強度データIとする。次にステージ
11を移動してこの過程を順次繰り返し,全ての露光位置
においてX線強度データIを求める。このIを式3に代
入して本発明による露光むらを求めると,第6図に示す
ように,±0.1%以内の誤差になることが分かる。Next, a measuring method based on the basic concept of the present invention will be described. First, as shown in FIG. 3, the stage 11 is moved so that the X-ray detector 4 comes to a predetermined exposure position, and the first filter 1 (Si 3 N 4 mask substrate 2 μm thick) is attached to the X-ray detector 4. Then, the X-ray mirror 10 is swung so that the X-ray 8 passes above the X-ray detector 4, the intensity of the X-ray 8 is measured through the first filter 1, and the output is I Set to 1 . Then, the filter holder 3 is rotated by the holder driving unit 5 so that the second filter 2 is located above the X-ray detector 4, and the X-ray intensity is measured through the second filter 2. Let its output be I 2 . The second filter 2
Is a structure in which PMMA resist is applied to a thickness of about 1 μm on a Si 3 N 4 mask substrate (about 2 μm in thickness). The difference (= I 1 −I 2 ) between I 1 and I 2 measured in this way is obtained, and this is taken as the X-ray intensity data I at that position. Next stage
11 is moved and this process is sequentially repeated to obtain X-ray intensity data I at all exposure positions. By substituting this I into the equation 3 to obtain the exposure unevenness according to the present invention, it is understood that the error is within ± 0.1% as shown in FIG.
このようにして求めたIに反比例するように各位置y
での相対露光時間T′e(y)を決定する。実際の露光
時間TeとT′eとの間の比例定数は,レジストの感度,
目標とする露光現像後のレジスト線幅および露光時のX
線強度により定まる。露光時のX線強度の測定は本発明
で用いたX線検出器4によって行ってもよいし,別の検
出器を用いてもよい。或いは,SRリングの露光時の電流
値から求めてもよい。各位置での露光時間が決定された
露光時間TeとなるようにX線ミラー10の揺動速度を変え
ながら露光を行う。Each position y is inversely proportional to I thus obtained.
The relative exposure time T'e (y) at is determined. The constant of proportionality between the actual exposure time Te and T'e is the sensitivity of the resist,
Target resist line width after exposure and development and X at exposure
Determined by line strength. The X-ray intensity at the time of exposure may be measured by the X-ray detector 4 used in the present invention, or another detector may be used. Alternatively, it may be obtained from the current value during exposure of the SR ring. The exposure is performed while changing the swing speed of the X-ray mirror 10 so that the exposure time Te at each position becomes the determined exposure time Te.
以上説明したように,本発明によって露光むらに対し
て著しい改善が得られることが分かった。また,本発明
をミラー揺動法で説明したが,本発明はこれに限定され
ず,固定ミラー法による露光その他広く一般に露光装置
の露光むらを検出するのに有効である。なお,固定ミラ
ー法では,X線検出器4を固定しフィルターを交換してX
線強度を測定する他,フィルターを固定してX線検出器
4を連続的に移動させて測定した後,再度フィルターを
交換してX線強度を測定すれば,連続的なX線強度分布
が得られる。また,両フィルター1,2のマスク基板およ
びそれに塗布されたレジスト層の厚さは露光用マスクお
よびレジスト層の厚さと必ずしも一致させる必要はな
い。As described above, it was found that the present invention can significantly improve uneven exposure. Further, although the present invention has been described using the mirror swing method, the present invention is not limited to this, and is generally effective for detecting exposure unevenness of an exposure apparatus such as exposure by a fixed mirror method. In the fixed mirror method, the X-ray detector 4 is fixed, the filter is replaced, and X
In addition to measuring the line intensity, if the filter is fixed and the X-ray detector 4 is continuously moved for measurement, then the filter is exchanged again and the X-ray intensity is measured. can get. Moreover, the thickness of the mask substrate of both filters 1 and 2 and the resist layer applied thereto need not necessarily match the thickness of the exposure mask and the resist layer.
本発明の別の実施例について以下に説明する。第1図
では3個のX線透過穴を有するフィルターホルダ3を示
したが,フィルターホルダ3に取付けられているフィル
ターはさらに多くてもよい。この場合,異なる材質のマ
スク基板材,レジスト材,あるいは異なる厚さのマスク
基板材,レジスト材をフィルターとして用いてもよい。
さらに,X線分光強度が等しい方向,即ち水平方向に校正
されたX線検出器を複数設置し各フィルター1,2を通し
たX線強度を同時に測定することも可能である。Another embodiment of the present invention will be described below. Although FIG. 1 shows the filter holder 3 having three X-ray transmission holes, more filters may be attached to the filter holder 3. In this case, mask substrate materials and resist materials of different materials, or mask substrate materials and resist materials of different thicknesses may be used as the filter.
Furthermore, it is also possible to install a plurality of X-ray detectors calibrated in the same X-ray spectral intensity direction, that is, in the horizontal direction, and simultaneously measure the X-ray intensity through each filter 1, 2.
第7図に示すように,パターンを有しないマスクの半
面にレジストを塗布し,レジストが塗布された側(図中
A)と塗布されてない側(図中B)をX線検出器で測定
しその差分をとることによりX線強度データIを得ても
よい。この実施例では位置A,BによってX線の分光強度
が変化しないように測定することが重要である。そのた
めには,ミラー揺動法や固定ミラー法においては,位置
A,Bを同一の水平面方向にとることが考えられる。また,
X線検出器4を移動させずにマスク12を移動させてもよ
い。さらに,一枚のマスク基板に異なる種類または厚さ
のレジストを塗布してもよい。その場合,同一マスク基
板の表裏に塗布してもよい。この実施例によれば,フィ
ルターやフィルターホルダ等の特別な装置を用意する必
要がなく,マスクの交換のみで測定できる。As shown in FIG. 7, resist is applied to the half surface of the mask having no pattern, and the side where the resist is applied (A in the figure) and the side where it is not applied (B in the figure) are measured with an X-ray detector. Then, the X-ray intensity data I may be obtained by taking the difference. In this embodiment, it is important to measure so that the X-ray spectral intensity does not change depending on the positions A and B. For that purpose, in the mirror swing method and fixed mirror method, the position
It is conceivable to take A and B in the same horizontal plane direction. Also,
The mask 12 may be moved without moving the X-ray detector 4. Furthermore, one mask substrate may be coated with resists of different types or thicknesses. In that case, it may be applied to the front and back of the same mask substrate. According to this embodiment, it is not necessary to prepare a special device such as a filter or a filter holder, and the measurement can be performed only by exchanging the mask.
第8図および第9図に本発明のさらに別の実施例を示
す。図示したように,一枚の薄膜上にレジストを塗布し
分けた構造のフィルターをフィルターホルダ3に取付
け,フィルター駆動部5によって回転させることにより
レジストが塗布された部分と塗布されない部分を透過し
たX線が交互にX線検出器に入射し2種のX線強度信号
を交互に得ることができ,さらにX線検出器は両者のX
線強度差検出ができる回路13,例えばハイパスフィルタ
ー等に接続されている。このような構成の検出器では,
検出器部(検出器4,フィルターホルダ3,駆動部等を一体
にした部分)を移動させることにより連続的にかつ迅速
にX線強度差を検出できる他,別個に測定した後,差分
をとるより高精度に強度差を検出できる。8 and 9 show still another embodiment of the present invention. As shown in the figure, a filter having a structure in which a resist is applied on a single thin film is attached to the filter holder 3 and rotated by the filter driving unit 5 so that the portion where the resist is applied and the portion where the resist is not applied are transmitted. The X-ray detector can alternately obtain two kinds of X-ray intensity signals by alternately entering the X-ray detector.
It is connected to a circuit 13 capable of detecting a difference in line strength, such as a high-pass filter. In the detector with such a configuration,
X-ray intensity difference can be detected continuously and quickly by moving the detector part (the part where detector 4, filter holder 3, drive part, etc. are integrated), and the difference can be obtained after individual measurement. The intensity difference can be detected with higher accuracy.
以上の実施例では,強度むらの測定中にX線強度が変
化しないとして説明したが,電子ビームの半減期が短い
場合,測定中にX線強度が減衰することがある。この場
合には,測定値I(y)に補正をかけることが可能であ
る。補正方法として,計算による方法と測定による方法
がある。測定による方法は,本発明とは別の検出器(出
力Ip)によって強度むら測定中のX線強度の減衰を測定
し,X線強度データI(y)にフィードバックしI(y)
に補正をかければよい。例えばIpを一定の位置で測定す
る場合,位置yのX線強度データをI(y),測定時の
X線強度をIp(y)とすれば,真のX線強度データIt
(y)は次式で表せる。Although the X-ray intensity does not change during the measurement of the intensity unevenness in the above embodiments, the X-ray intensity may be attenuated during the measurement when the electron beam has a short half-life. In this case, the measured value I (y) can be corrected. As the correction method, there are a calculation method and a measurement method. The measurement method measures the attenuation of the X-ray intensity during intensity unevenness measurement by a detector (output Ip) different from the present invention, and feeds back the X-ray intensity data I (y) to I (y).
You can correct it. For example, when Ip is measured at a fixed position, if the X-ray intensity data at position y is I (y) and the X-ray intensity at measurement is Ip (y), the true X-ray intensity data It
(Y) can be expressed by the following equation.
It(y)=I(y)*(Ip(o)/Ip(y)) さらに,補正を電気的に行うことも可能である。例え
ば,Ipを除算回路の分母入力とし,I(y)を分子入力と
すれば,除算回路の出力としてIt(y)が得られる。ま
た,計算による方法は幾つか考えられるが,例えば電子
ビームの寿命のτとし,さらにX線強度データ測定開始
時の時刻を0とし,位置yの測定時刻をtとすれば It(y)=I(y)*exp(t/τ) と補正することも可能である。It (y) = I (y) * (Ip (o) / Ip (y)) Further, it is possible to make the correction electrically. For example, if Ip is the denominator input of the division circuit and I (y) is the numerator input, It (y) is obtained as the output of the division circuit. There are several possible calculation methods. For example, if the electron beam lifetime is τ, the time at the start of X-ray intensity data measurement is 0, and the measurement time at position y is t, It (y) = It is also possible to correct it as I (y) * exp (t / τ).
以上説明したように,本発明においては,高精度でか
つ短時間でウェハ面上の露光分布を測定し露光むらを極
めて少ないウェハ露光を可能とする露光強度測定方法が
達成される。As described above, according to the present invention, an exposure intensity measuring method is achieved which can measure the exposure distribution on the wafer surface with high accuracy and in a short time and can perform wafer exposure with extremely small exposure unevenness.
第1図は本発明方法を実施するための装置の一例の斜視
図,第2図は第1図のA−A断面図,第3図は本発明に
係わる露光装置の概念図,第4図はミラー揺動における
X線の分光強度のグラフ,第5図は従来技術による露光
むらを示すグラフ,第6図は本発明による露光むらを示
すグラフ,第7図は本発明の別の実施例を示す断面図,
第8図は本発明のさらに別の実施例の斜視図,第9図は
第8図のA−A断面図である。 1……第1のフィルター, 2……第2のフィルター, 3……フィルターホルダ, 4……X線強度検出器, 5……ホルダ駆動部, 8……X線。FIG. 1 is a perspective view of an example of an apparatus for carrying out the method of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a conceptual view of an exposure apparatus according to the present invention, and FIG. Is a graph of the X-ray spectral intensity in the mirror swing, FIG. 5 is a graph showing exposure unevenness according to the prior art, FIG. 6 is a graph showing exposure unevenness according to the present invention, and FIG. 7 is another embodiment of the present invention. Cross section showing
FIG. 8 is a perspective view of still another embodiment of the present invention, and FIG. 9 is a sectional view taken along line AA of FIG. 1 ... 1st filter, 2 ... 2nd filter, 3 ... Filter holder, 4 ... X-ray intensity detector, 5 ... Holder drive part, 8 ... X-ray.
フロントページの続き (72)発明者 鵜澤 俊一 東京都大田区下丸子3丁目30番2号 キヤ ノン株式会社内 (72)発明者 刈谷 卓夫 東京都大田区下丸子3丁目30番2号 キヤ ノン株式会社内 (56)参考文献 特開 平2−71508(JP,A) 特開 平1−305518(JP,A)Front page continued (72) Inventor Shunichi Uzawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takuo Kariya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-2-71508 (JP, A) JP-A-1-305518 (JP, A)
Claims (10)
ターンを露光転写する露光装置における露光領域での露
光用光線強度分布測定方法であって,露光領域の各点に
おいて,マスク基板と同一材料からなる第1のフィルタ
ーを透過する光線の強度と,前記マスク基板と同一材料
の基板上にレジストを塗布した第2のフィルターを透過
する光線の強度との差を検出し,該検出結果に基づいて
前記露光領域各点での光線強度を求めることを特徴とす
る露光強度測定方法。1. A method of measuring a light intensity distribution for exposure in an exposure area in an exposure device for exposing and transferring a pattern of a mask onto a wafer coated with a resist, wherein each point of the exposure area is made of the same material as the mask substrate. Detecting the difference between the intensity of the light beam passing through the first filter and the intensity of the light beam passing through the second filter formed by coating a resist on the same substrate as the mask substrate, and based on the detection result An exposure intensity measuring method, characterized in that a light intensity at each point of the exposure region is obtained.
ターを回転可能なフィルターホルダに装着し,該フィル
ターホルダを移動ステージ上に設け,該移動ステージを
駆動してフィルターホルダを露光領域各点に対応した位
置に移動させ,各位置においてフィルターホルダを回転
させて第1および第2の各フィルターを通過する光線の
強度を検出することを特徴とする特許請求の範囲第1項
記載の露光強度測定方法。2. The first filter and the second filter are mounted on a rotatable filter holder, the filter holder is provided on a moving stage, and the moving stage is driven to move the filter holder to each point of an exposure area. The exposure intensity measurement according to claim 1, wherein the intensity of a light beam passing through each of the first and second filters is detected by moving to a corresponding position and rotating the filter holder at each position. Method.
し,前記第2のフィルターを該マスク基板にレジストを
塗布して構成したことを特徴とする特許請求の範囲第1
項記載の露光強度測定方法。3. The mask substrate itself is used as the first filter, and the second filter is formed by applying a resist to the mask substrate.
The method for measuring exposure intensity according to the item.
る光線強度を交互に連続的に検出して両者の差を計測す
ることを特徴とする特許請求の範囲第1項記載の露光強
度測定方法。4. The exposure intensity measurement according to claim 1, wherein the intensity of light passing through the first and second filters is alternately and continuously detected to measure the difference between the two. Method.
て前記第1および第2のフィルターを通過する光線強度
の差を求めることを特徴とする特許請求の範囲第1項か
ら第4項までのいずれか1項記載の露光強度測定方法。5. The method according to claim 1, wherein a change in intensity of the exposure light beam with time is corrected to obtain a difference between the intensities of the light beams passing through the first and second filters. The method for measuring exposure intensity according to any one of items 1 to 7.
ルターと,前記マスク基板と同一材料の基板上にレジス
トを塗布した第2のフィルターと,該第1および第2の
各フィルターを通過した光線を検出するための光検出器
と,前記各フィルターを該光検出器上に移動させるため
のフィルター移動手段と,該光検出器を露光領域各点に
移動させるための測定位置移動手段とを具備したことを
特徴とする特許請求の範囲第1項記載の方法を実施する
ための露光強度測定装置。6. A first filter made of the same material as the mask substrate, a second filter in which a resist is applied on a substrate made of the same material as the mask substrate, and passed through each of the first and second filters. A photodetector for detecting the light beam, a filter moving means for moving the filters on the photodetector, and a measurement position moving means for moving the photodetector to each point of the exposure area. An exposure intensity measuring apparatus for carrying out the method according to claim 1, which is provided.
したフィルターホルダおよび該フィルターホルダの回転
手段を備え,該フィルターホルダに隣接して前記光検出
器を設け,該フィルターホルダを回転させることにより
前記各フィルターを通過する光線を順番に前記光検出器
で検出可能に構成したことを特徴とする特許請求の範囲
第6項記載の露光強度測定装置。7. A filter holder equipped with the first and second filters and a rotating means for the filter holder, the photodetector is provided adjacent to the filter holder, and the filter holder is rotated. 7. The exposure intensity measuring apparatus according to claim 6, wherein the light beam passing through each of the filters is sequentially detected by the photodetector.
構成し,前記第2のフィルターを該マスク基板にレジス
トを塗布して構成したことを特徴とする特許請求の範囲
第6項記載の露光強度測定装置。8. The exposure according to claim 6, wherein the first filter is constituted by a mask substrate itself, and the second filter is constituted by coating a resist on the mask substrate. Strength measuring device.
する光線を交互に連続的に測定する手段を備えたことを
特徴とする特許請求の範囲第6項記載の露光強度測定装
置。9. The exposure intensity measuring device according to claim 6, further comprising means for alternately and continuously measuring the light rays passing through the first and second filters.
して前記各フィルターの透過光線強度の差を求める補正
手段を具備したことを特徴とする特許請求の範囲第6項
から第9項までのいずれか1項記載の露光強度測定装
置。10. The method according to claim 6, further comprising a correction unit that corrects a temporal intensity change of the exposure light beam to obtain a difference in transmitted light beam intensity of each of the filters. The exposure intensity measuring device according to any one of 1 to 6 above.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63228389A JPH0821536B2 (en) | 1988-09-14 | 1988-09-14 | Exposure intensity measurement method |
DE68929356T DE68929356T2 (en) | 1988-06-03 | 1989-06-05 | Exposure method and apparatus |
EP89305669A EP0345097B1 (en) | 1988-06-03 | 1989-06-05 | Exposure method and apparatus |
US07/769,493 US5131022A (en) | 1988-06-03 | 1991-10-01 | Exposure method and apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63228389A JPH0821536B2 (en) | 1988-09-14 | 1988-09-14 | Exposure intensity measurement method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0277627A JPH0277627A (en) | 1990-03-16 |
JPH0821536B2 true JPH0821536B2 (en) | 1996-03-04 |
Family
ID=16875704
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63228389A Expired - Fee Related JPH0821536B2 (en) | 1988-06-03 | 1988-09-14 | Exposure intensity measurement method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0821536B2 (en) |
-
1988
- 1988-09-14 JP JP63228389A patent/JPH0821536B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH0277627A (en) | 1990-03-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5303282A (en) | Radiation imager collimator | |
EP0345097B1 (en) | Exposure method and apparatus | |
JPH0648380B2 (en) | Mask inspection method | |
CN107250766A (en) | Optical metrology with reduced focusing error sensitivity | |
US6963395B2 (en) | Method and apparatus for inspecting an EUV mask blank | |
EP1462780A1 (en) | Apparatus and method for measuring EUV light intensity distribution | |
JPH0722109B2 (en) | Method for determining light exposure of photosensitive rack layer | |
JPH0821536B2 (en) | Exposure intensity measurement method | |
US20050184247A1 (en) | Device for measuring angular distribution of EUV light intensity, and method for measuring angular distribution of EUV light intensity | |
JP3285309B2 (en) | Photo detector | |
JPS59188931A (en) | Height measuring apparatus for wafer | |
JP2638914B2 (en) | X-ray intensity measurement method for exposure | |
JP2675859B2 (en) | X-ray mask and X-ray exposure method using the same | |
JPH03246452A (en) | Total reflecting fluorescent x-ray analyzing instrument | |
JP3272788B2 (en) | X-ray intensity measurement device | |
JPS62269036A (en) | System for automatically measuring diffraction efficiency distribution of diffraction grating | |
JPH0429012B2 (en) | ||
JP2622318B2 (en) | X-ray exposure mask | |
JP2952284B2 (en) | X-ray optical system evaluation method | |
JP3221711B2 (en) | X-ray position sensor and exposure apparatus using the same | |
JP2795005B2 (en) | Detector of tilt angle between the optical axis of synchrotron radiation and the axis of exposure equipment | |
JPS59120909A (en) | Method for measuring thickness of resist coated film | |
JP3105233B2 (en) | X-ray mask inspection equipment | |
JPH05188149A (en) | X-ray-wavelength estimating method | |
JP2877352B2 (en) | X-ray exposure equipment |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees |