JPH0441484B2 - - Google Patents
Info
- Publication number
- JPH0441484B2 JPH0441484B2 JP58175353A JP17535383A JPH0441484B2 JP H0441484 B2 JPH0441484 B2 JP H0441484B2 JP 58175353 A JP58175353 A JP 58175353A JP 17535383 A JP17535383 A JP 17535383A JP H0441484 B2 JPH0441484 B2 JP H0441484B2
- Authority
- JP
- Japan
- Prior art keywords
- grating
- light
- interference fringes
- alignment
- wafer
- 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 - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 17
- 230000001427 coherent effect Effects 0.000 claims description 6
- 230000003287 optical effect Effects 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 4
- 230000004907 flux Effects 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000000206 photolithography Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 241000213951 Salmonella enterica subsp. enterica serovar Austin Species 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001093 holography Methods 0.000 description 1
- 238000005305 interferometry Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7049—Technique, e.g. interferometric
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70408—Interferometric lithography; Holographic lithography; Self-imaging lithography, e.g. utilizing the Talbot effect
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7073—Alignment marks and their environment
- G03F9/7076—Mark details, e.g. phase grating mark, temporary mark
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Control Of Position Or Direction (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、精度の高い位置合わせ装置、特に高
密な半導体装置（以下LSIとよぶ）の位置合わせ
装置に適用できる位置合わせ方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a positioning method that can be applied to a highly accurate positioning apparatus, particularly to a positioning apparatus for high-density semiconductor devices (hereinafter referred to as LSI).
従来例の構成とその問題点
半導体装置は最近ますます高密度化され、各々
の素子の微細パターンの寸法は１ミクロン以下に
及んでいる。従来からのLSI製造時のフオトマス
クとLSIウエハの位置合わせは、ウエハに設けた
位置合せマークを用いて、ウエハを着装したステ
ージの回転と２軸平行移動し、フオトマスク上の
マークとウエハ上のマークを重ね合わせることに
よつて行なつていたが、その位置合わせ精度は±
0.3ミクロン程度であり、サブミクロンの素子を
形成する場合には、合わせ精度が悪く実用になら
ない。また、S.オースチン（Applied physics
Letters Vol31No.7P.428，1977）らが示した干渉
法を用いた位置合わせ方法では、第１図で示した
ように、入射レーザビーム１をフオトマスク２に
入射させ、フオトマスク２上に形成した格子３で
回折し、この回折した光をもう一度、ウエハ４上
に形成した格子５によつて回折することにより、
回折光６，７，８……を得る。この回折光は、フ
オトマスクでの回折次数とウエハでの回折次数の
二値表示で表わすと、回折光６は０，１、回折光
７は１，１、回折光８は−１，２……で表わすこ
とができる。この回折光をレンズにより一点に集
め光強度を測定する。回折光は入射レーザビーム
１に対して左右対称な位置に光強度を持ち、フオ
トマスク２とウエハ４との位置合わせには、左右
に観察された回折光の強度を一致させることによ
り行なえる。この方法では位置合わせ精度は、数
１００Åとされている。しかし、この方法におい
ては、フオトマスク２とウエハ４との位置合わせ
は、フオトマスク２とウエハ４との間隔Ｄに大き
く影響されるため、間隔Ｄの精度を要求する。ま
た、フオトマスク２とウエハ４を接近させ、間隔
Ｄの精度を保持した状態で位置合わせする必要が
あり装置が複雑となるため、実用に問題があつ
た。Conventional Structure and Problems Semiconductor devices have recently become more and more densely packed, and the dimensions of the fine patterns of each element are now 1 micron or less. Conventionally, alignment between a photomask and an LSI wafer during LSI manufacturing is achieved by rotating and parallelly moving a stage on which the wafer is mounted, using alignment marks provided on the wafer, to align the marks on the photomask with the marks on the wafer. This was done by superimposing the images, but the alignment accuracy was ±
It is about 0.3 microns, and when forming submicron elements, the alignment accuracy is poor and it is not practical. Also, S. Austin (Applied physics
In the positioning method using interferometry shown in Letters Vol. 31 No. 7 P. 428, 1977, et al., as shown in 3, and this diffracted light is diffracted again by a grating 5 formed on the wafer 4,
Diffracted lights 6, 7, 8... are obtained. When this diffracted light is expressed as a binary representation of the diffraction order on the photomask and the diffraction order on the wafer, diffracted light 6 is 0,1, diffracted light 7 is 1,1, diffracted light 8 is -1,2... It can be expressed as This diffracted light is collected at one point by a lens and the light intensity is measured. The diffracted light has a light intensity at a position symmetrical to the incident laser beam 1, and the photomask 2 and the wafer 4 can be aligned by matching the intensities of the diffracted light observed on the left and right sides. In this method, the alignment accuracy is said to be several hundred angstroms. However, in this method, the alignment between the photomask 2 and the wafer 4 is greatly influenced by the distance D between the photomask 2 and the wafer 4, and therefore, the accuracy of the distance D is required. Further, it is necessary to bring the photomask 2 and the wafer 4 close to each other and align them while maintaining the accuracy of the distance D, which complicates the apparatus, which poses a problem in practical use.
また、サブミクロン線巾を持つ素子の位置合わ
せには、素子からの二次電子放出による観察によ
る方法があるが、大気中での取り扱いができない
ため、LSIを製造する上でのスループツトが小さ
くなり実用上問題があつた。 In addition, there is a method for aligning elements with submicron line widths through observation using secondary electron emission from the elements, but this method cannot be handled in the atmosphere, which reduces the throughput in manufacturing LSIs. There was a practical problem.
発明の目的
本発明はこのような従来からの問題に鑑み、微
細パターンの位置合わせを大気中で、かつ、簡単
な構成で行なえるLSIのフオトマスクとウエハの
正確かつ容易な位置合わせ方法を提供することを
目的としている。Purpose of the Invention In view of these conventional problems, the present invention provides an accurate and easy alignment method for an LSI photomask and a wafer, which allows alignment of fine patterns in the atmosphere and with a simple configuration. The purpose is to
発明の構成
本発明は、コヒーレントな光を二方向から入射
させ、この光の二光束の干渉により得られる干渉
縞に対して平行に配置された格子を前記二光束の
光路中に持ち、この格子によつて反射または透過
した光をレンズを通して集光し、光検知手段に導
き、この出力変化を測定することにより、前記二
光束の干渉縞と格子との相対位置を検知する方法
により、半導体微細素子の位置合わせを高精度に
行なうことを実現するものである。そして、基板
上の格子のピツチを干渉縞のピツチの整数倍とす
ることにより、ホトリングラフイ技術によつて位
置合わせ用の格子をLSIパターンを形成する際同
時に形成し、高精度の位置合わせを行うことので
きる方法を提供するものである。さらにまた、本
発明は、ウエハ上に位置合わせ用格子と、この格
子とは異なる図形を形成し、この図形を用いて概
略の位置合わせを行なつた後に、前記格子に対し
てコヒーレントな光を２方向から入射し、この２
光束の干渉により得られる干渉縞に対して略平行
に配置された格子を前記２光束の光路中に保ち、
前記格子によつて反射又は透過した光を光検知手
段に導びき、前記光検知器の出力変化を測定する
ことにより、前記２光束の干渉縞と前記格子との
相対位置を検知し、前記干渉縞に対し前記格子を
位置合わせする方法により、半導体微細素子の位
置合わせを高精度に行なうことを実現するもので
ある。Structure of the Invention The present invention allows coherent light to enter from two directions, and has a grating in the optical path of the two beams that is arranged parallel to the interference fringes obtained by interference of the two beams of light, and the grating. The method detects the relative position between the interference fringes of the two beams and the grating by focusing the light reflected or transmitted by the lens through a lens, guiding it to the light detection means, and measuring the change in output. This realizes highly accurate positioning of elements. Then, by making the pitch of the grating on the substrate an integral multiple of the pitch of the interference fringes, the grating for alignment can be formed at the same time as forming the LSI pattern using photolithography technology, and high-precision alignment can be achieved. This provides a method that allows you to do this. Furthermore, in the present invention, an alignment grating and a shape different from the grating are formed on the wafer, and after rough alignment is performed using this shape, coherent light is emitted to the grating. It is incident from two directions, and these two
A grating arranged substantially parallel to interference fringes obtained by interference of the light beams is maintained in the optical path of the two light beams,
By guiding the light reflected or transmitted by the grating to a photodetector and measuring the change in the output of the photodetector, the relative position between the interference fringes of the two light beams and the grating is detected, and the interference pattern is detected. By the method of aligning the grating with respect to the stripes, it is possible to align the semiconductor micro elements with high precision.
実施例の説明
第２図に本発明による位置検知方法を実施でき
るホログラフイツク露光装置および光検知器を具
備した位置合わせ装置を示した。コヒーレントな
光１０をレーザー発生装置からビームスプリツタ
（BS）に入射させ、ほぼ同一強度の反射光１１と
透過光１２とに振幅分割し、各々反射鏡M1と反
射鏡M2に入射し、ウエハＷの表面に対して双方
の反射光がほぼ等しい角度θで入射するように、
Ｂ，Ｓ，M1，M2，Ｗを配置する。ウエハ（半導
体基板）Ｗ上には格子Ｇが形成されており、格子
Ｇによつて回折した反射光１３および１４が、
各々レンズL1およびL2を通して光検知器D1およ
びD2に入射する。なお、格子Ｇはウエハの所定
領域に規則的に形成したくり返しパターンを用い
ればよい。DESCRIPTION OF THE EMBODIMENTS FIG. 2 shows a positioning device equipped with a holographic exposure device and a photodetector that can carry out the position detection method according to the present invention. Coherent light 10 is incident on a beam splitter (BS) from a laser generator, and is amplitude-divided into reflected light 11 and transmitted light 12 of approximately the same intensity, which are incident on a reflecting mirror M1 and a reflecting mirror M2 , respectively, so that both reflected lights are incident on the surface of the wafer W at approximately the same angle θ.
Place B, S, M 1 , M 2 and W. A grating G is formed on the wafer (semiconductor substrate) W, and reflected lights 13 and 14 diffracted by the grating G are
The light enters photodetectors D 1 and D 2 through lenses L 1 and L 2 , respectively. Note that the grating G may be a repeating pattern regularly formed in a predetermined area of the wafer.
レーザの波長をλ，M1，M2からの反射光１
１，１２が干渉して作る干渉縞のピツチをΛとす
ると、ウエハ上にできる干渉縞は、
Λ＝λ／2sinθで表わせる。 The wavelength of the laser is λ, and the reflected light from M 1 and M 2 is 1
Let Λ be the pitch of the interference fringes created by the interference of 1 and 12, then the interference fringes created on the wafer can be expressed as Λ=λ/2sinθ.
この干渉縞のピツチΛにほぼ等しいピツチを持つ
格子Ｇからは、２光束１１と１２の干渉した光を
波面分割する格子Ｇによつて回折された光が得ら
れ、さらにレンズL1，L2を通して波面分割され
た光を集束して干渉させると２光束の干渉縞と格
子Ｇとの間の位置関係を示す光強度情報が得られ
る。光検知器D1およびD2上での観測される光強
度Ｉは
Ｉ＝uA 2＋uB 2＋uA *・uB＋uA・uB *
ただし、uA，uBは各々光束１１，１２の振幅強
度uA *，uB *は、共役複素振幅である。From the grating G, which has a pitch approximately equal to the pitch Λ of this interference fringe, light is obtained which is diffracted by the grating G, which splits the wavefront of the two light beams 11 and 12 that have interfered, and further by the lenses L 1 and L 2 When the wavefront-split light is focused and interfered with, light intensity information indicating the positional relationship between the interference fringes of the two beams and the grating G is obtained. The light intensity I observed on the photodetectors D 1 and D 2 is I = u A 2 + u B 2 + u A *・u B + u A・u B * However, u A and u B are the luminous flux 11, The amplitude intensities u A * and u B * of 12 are conjugate complex amplitudes.
uA 2＝A2（sinNδA／２／sinδA／２）2，uB 2＝B2（si
nNδB／２／sinδB／２）2
uA *・uB＋uA・uB *＝２・Ａ・Bcos｛（Ｎ−１）
δA−δB／２
＋kx（sinθA−sinθB）｝×sinNδA／２・sinNδB
／２／sinδA／２・sinδB／２
（ただし、Ａ，Ｂは定数、Ｎ：格子の数、δA，
δBは隣接した２格子によつて回折された光の間の
光路差、ｘは光束１１と光束１２との干渉縞と格
子との間の相対的位置関係、θA，θBは光束１１及
び１２とウエハの垂線とのなす角）として示され
る。第３図はウエハが光を透過する場合の位置合
わせ装置の配置を示したものであり、光検知器
D3，D4及び光学系L1，L2がウエハＷの後方に位
置している。 u A 2 = A 2 (sinNδ A /2/sinδ A /2) 2 , u B 2 = B 2 (si
nNδ B /2/sinδ B /2) 2 u A *・u B +u A・u B * =2・A・Bcos {(N-1)
δ A −δ B /2 +kx(sinθ A −sinθ B )}×sinNδ A /2・sinNδ B
/2/sinδ A /2・sinδ B /2 (where, A and B are constants, N: number of lattices, δ A ,
δ B is the optical path difference between the lights diffracted by two adjacent gratings, x is the relative positional relationship between the interference fringes of light beams 11 and 12 and the gratings, and θ A and θ B are the light beams 11 and 12 and the perpendicular to the wafer). Figure 3 shows the arrangement of the alignment device when the wafer transmits light.
D 3 , D 4 and optical systems L 1 , L 2 are located behind the wafer W.
次に、第４図に光強度Ｉの観測角度依存性を示
した。干渉縞のピツチを1μm、格子のピツチを
2μmとした場合の図である。光強度に鋭いピーク
が現われるのは光強度Ｉで示されているように、
干渉縞のピツチに対し格子のピツチが整数倍のと
きに限られている。そして、第４図において、観
測角度を０〜π／２と変化させると５つのピーク
があらわれ、θ2のピークには、入射光１１，１２
の０次の回折光が重なる。θ4のピークは干渉縞と
格子のピツチが等しい場合の１次の回折光が含ま
れている。θ1〜θ5の各々のピークに干渉縞とウエ
ハ上の格子との間の位置情報が含まれている。 Next, FIG. 4 shows the observation angle dependence of the light intensity I. The pitch of the interference fringes is 1μm, and the pitch of the grating is
This is a diagram when the thickness is 2 μm. A sharp peak appears in the light intensity, as shown by light intensity I.
This is limited to cases where the pitch of the grating is an integral multiple of the pitch of the interference fringes. In Fig. 4, five peaks appear when the observation angle is changed from 0 to π/2, and the peak at θ 2 includes incident light 11, 12
The 0th order diffracted lights of the two overlap. The peak at θ 4 includes first-order diffracted light when the interference fringes and the grating pitch are equal. Each peak of θ 1 to θ 5 contains positional information between the interference fringe and the grating on the wafer.
第５図に、光検出器の位置を第４図のピークを
示す位置に固定し、光束１１と光束１２の作る干
渉縞とウエハ上の格子との間の相対位置ｘを変化
させたときの光強度Ｉの変化を示した。相対位置
ｘの変化は、格子のピツチ毎に光強度を周期的
に変化させ、光強度を観測することによつて、干
渉縞と格子との間の相対位置を示すことができ
る。 FIG. 5 shows the results when the position of the photodetector is fixed at the position showing the peak in FIG. 4 and the relative position x between the interference fringes formed by the light beams 11 and 12 and the grating on the wafer is changed. The change in light intensity I is shown. By changing the relative position x, the light intensity is periodically changed for each pitch of the grating, and by observing the light intensity, the relative position between the interference fringes and the grating can be indicated.
実際のLSIのパターンを形成するときの位置合
わせは、ウエハ上に形成された回路素子部分のパ
ターンと露光しようとする二光束の干渉縞との間
の位置合わせである。第６図は、その様子を示し
た。ウエハＷ上には回折格子２０とゲートパター
ン２１とが従来からのホトリソグラフイによつて
形成されている。この回折格子２０は、ゲートパ
ターン２１と正確に位置決めされており、たとえ
ば、チツプ間に位置しているチツプ切断用の余白
（スクライブライン）に設けることができる。格
子２０のピツチは光露光やＸ線露光で正確に形成
できる範囲の干渉縞のピツチに対して整数倍の線
巾に形成されている。干渉縞２２はウエハ全体又
は位置合わせ用の格子２０に照射され格子２０と
干渉縞２２の相対的な位置合わせが行なわれると
ともに、パターン２１と干渉縞２２との間の相対
的な位置合わせを行なうことができる。 The alignment when forming the actual LSI pattern is the alignment between the pattern of the circuit element portion formed on the wafer and the interference fringes of the two beams to be exposed. Figure 6 shows this situation. A diffraction grating 20 and a gate pattern 21 are formed on the wafer W by conventional photolithography. This diffraction grating 20 is accurately positioned with the gate pattern 21, and can be provided, for example, in a margin for chip cutting (scribe line) located between chips. The pitch of the grating 20 is formed to have a line width that is an integral multiple of the pitch of interference fringes that can be accurately formed by light exposure or X-ray exposure. The interference fringes 22 are irradiated onto the entire wafer or the alignment grating 20, and the grating 20 and the interference fringes 22 are aligned relative to each other, and the pattern 21 and the interference fringes 22 are also aligned relative to each other. be able to.
第７図に従来からの位置合わせマークＭと格子
Ｇとを組み合わせた場合の位置合わせパターンを
示した。図に示されているように、十字の位置合
わせマークＭが格子Ｇのパターンの中に形成され
ている。この格子に十字の位置合わせマークの入
つたパターンに二光束を照射すると、第７図のパ
ターンからの回折光は四辺形の明パターンの中に
十字の暗パターンが組み合わさつたもので、位置
合わせが不十分であると第８図ａのように十字の
暗パターンが二実に見える状態となり、第８図ｂ
のように十字のパターンを合わせるべく位置合せ
を行う。すなわち、この十字のパターンに合わせ
て光検知手段を設けると従来と同様のパターン位
置合わせを行なうことができる。こうして従来と
同様の位置合わせ方法によつて0.3ミクロン程度
の概略の位置合わせができる。こうして位置合わ
せが終ると、第８図ｂに示したように、四辺形の
明パターンの中にモアレ状縞が観測されるように
なり、この縞を用いて本発明の位置合わせ方法に
より短時間に高精度の位置合わせを行なうことが
できる。 FIG. 7 shows an alignment pattern when a conventional alignment mark M and a grating G are combined. As shown in the figure, a cross-shaped alignment mark M is formed in the pattern of the grating G. When two beams of light are irradiated onto a pattern with a cross alignment mark on this grating, the diffracted light from the pattern in Figure 7 is a combination of a dark cross pattern in a bright quadrilateral pattern, and alignment is difficult. If it is insufficient, the dark pattern of the cross will appear double as shown in Figure 8a, and as shown in Figure 8b.
Perform alignment to match the cross pattern as shown. That is, by providing a light detection means in accordance with this cross pattern, pattern positioning can be performed in the same way as in the conventional method. In this way, rough alignment of about 0.3 microns can be achieved using the same alignment method as in the past. When the alignment is completed in this way, as shown in FIG. It is possible to perform highly accurate positioning.
以上、本発明による実施例では、半導体装置の
製造に用いる露光装置においてウエハ上に形成さ
れているパターンと露光しようとするパターンと
の間の高精度の位置合わせについて述べた。本位
置合わせののち行う露光方法はホログラフイ法に
よる二光束干渉縞の露光、従来からのホトリソグ
ラフイ、縮小投影露光、Ｘ線露光、電子ビーム露
光等を用いることができる。 The embodiments according to the present invention have described highly accurate positioning between a pattern formed on a wafer and a pattern to be exposed in an exposure apparatus used for manufacturing semiconductor devices. As the exposure method to be performed after this alignment, two-beam interference fringe exposure using holography, conventional photolithography, reduction projection exposure, X-ray exposure, electron beam exposure, etc. can be used.
発明の効果
以上のように、本発明は互いに共役な光束を干
渉させ、その結果得られた干渉縞とウエハ上に形
成した干渉縞のピツチに対して整数倍のピツチの
格子を相対的に位置合わせすることにより、格子
から反射又は透過して波面分割された光を再び干
渉させて光強度を観測すると、２光束の干渉縞と
格子との間の相対位置を読み取ることができ、精
度の高い位置合わせが可能となる。又、本発明で
は位置合わせ格子のピツチが干渉縞の整数倍で良
いため、半導体プロセスに応じて、位置合わせ格
子の変形を受けない位置合わせ格子の選択が可能
となる。また、本発明は、ウエハ上に位置合わせ
格子と該格子とは異なる図形を形成し、この図形
を用いて概略の位置合わせを行なつた後に、ウエ
ハ上に生成した２光束干渉縞とウエハ上の格子の
位置合わせが行なえるため、本位置合わせの特長
であるウエハ上の格子と２光束干渉縞の周期的な
位置合わせずれが発生しないで、精度の高い位置
合わせが可能となる。Effects of the Invention As described above, the present invention allows mutually conjugate light beams to interfere with each other, and positions a grating with a pitch that is an integer multiple of the interference fringes obtained as a result and the pitch of the interference fringes formed on the wafer. By combining the waves, the light that has been reflected or transmitted from the grating and split into wavefronts is allowed to interfere again and the light intensity is observed. The relative position between the interference fringes of the two beams and the grating can be read with high accuracy. Positioning becomes possible. Further, in the present invention, since the pitch of the alignment grating can be an integral multiple of the interference fringes, it is possible to select an alignment grating that is not subject to deformation depending on the semiconductor process. Further, the present invention forms an alignment grating and a figure different from the grating on the wafer, and after performing rough alignment using this figure, the two-beam interference fringes generated on the wafer and the Since the gratings can be aligned, the periodic misalignment between the grating on the wafer and the two-beam interference fringes, which is a feature of this alignment, does not occur, and highly accurate alignment is possible.
又、本発明に用いられる概略位置合わせマーク
は格子マークと共用できるため、ウエハチツプ内
の位置合わせマークの占有面積を小さくする事が
出来る。さらに本発明の位置合わせ後の露光方法
は、従来からのホトリソグラフイ法，縮小投影露
光、Ｘ線露光、電子ビーム露光等を用いる事が可
能である。 Furthermore, since the general alignment mark used in the present invention can be used in common with the grid mark, the area occupied by the alignment mark within the wafer chip can be reduced. Further, as the exposure method after alignment of the present invention, conventional photolithography, reduction projection exposure, X-ray exposure, electron beam exposure, etc. can be used.
第１図は従来例による位置合わせの説明図、第
２図は本発明による反射型の位置合わせ装置の概
略構成図、第３図は本発明による透過型の位置合
わせ装置の概略構成図、第４図は光検知器によつ
て観測される光強度の観測角依存性を示す図、第
５図は光検知器によつて観測される光強度の変位
依存性を示す図、第６図は本発明によるウエハ上
のパターンの位置合わせを説明する平面図、第７
図は本発明による位置合わせと従来からの位置合
わせマークとの並用を示す平面図、第８図ａ，ｂ
は第７図の位置合わせマークによる位置合わせの
説明図である。
１０……コヒーレント光、１１……反射光、１
２……透過光、２０……格子、２２……干渉縞、
Ｗ……ウエハ、Ｇ……格子、D1，D2……光検知
器、Ｍ……位置合わせマーク。
FIG. 1 is an explanatory diagram of alignment according to a conventional example, FIG. 2 is a schematic diagram of a reflective type alignment device according to the present invention, and FIG. 3 is a schematic diagram of a transmission type alignment device according to the present invention. Figure 4 shows the observation angle dependence of the light intensity observed by the photodetector, Figure 5 shows the displacement dependence of the light intensity observed by the photodetector, and Figure 6 shows the dependence of the light intensity observed by the photodetector on displacement. Seventh plan view illustrating alignment of patterns on a wafer according to the present invention.
The figure is a plan view showing the simultaneous use of the alignment according to the present invention and the conventional alignment mark, FIGS. 8a and 8b.
7 is an explanatory diagram of positioning using the positioning marks of FIG. 7. FIG. 10...Coherent light, 11...Reflected light, 1
2... transmitted light, 20... grating, 22... interference fringe,
W...Wafer, G...Grating, D1 , D2 ...Photodetector, M...Positioning mark.
Claims (1)
二光束の干渉により得られる干渉縞に対して略平
行に配置された格子を前記二光束の光路中に持
ち、前記格子のピツチが前記干渉縞のピツチの整
数倍に形成されており、前記格子によつて反射又
は透過した光を光検知手段に導びき、前記光検知
器の出力変化を測定することにより前記二光束の
干渉縞と前記格子との相対位置を検知し、前記干
渉縞に対し前記格子を位置合わせすることを特徴
とする位置合わせ方法。 ２ ウエハ上に位置合わせ用格子と、この格子の
周期とは異なる図形を形成し、この図形を用いて
概略の位置合わせを行なつた後に、前記格子に対
してコヒーレントな光を二方向から入射し、この
二光束の干渉により得られる干渉縞に対して略平
行に配置された格子を前記二光束の光路中に有し
前記格子によつて反射又は透過した光を光検知手
段に導びき、前記光検知器の出力変化を測定する
ことにより、前記二光束の干渉縞と前記格子との
相対位置を検知し、前記干渉縞に対し前記格子を
位置合わせすることを特徴とする位置合わせ方
法。 ３ ウエハ上に形成した格子の周期とは異なる図
形を、前記格子に対して重ねて形成することを特
徴とする特許請求の範囲第２項記載の位置合わせ
方法。[Scope of Claims] 1 Coherent light is incident from two directions, and a grating is provided in the optical path of the two light beams, the grating being arranged approximately parallel to the interference fringes obtained by interference of the two light beams, The pitch is formed to be an integer multiple of the pitch of the interference fringes, and the light reflected or transmitted by the grating is guided to a photodetector and the change in the output of the photodetector is measured, thereby converting the two luminous fluxes. A positioning method comprising detecting a relative position between interference fringes and the grating, and aligning the grating with respect to the interference fringes. 2. After forming an alignment grating on the wafer and a figure with a period different from that of the grating, and performing approximate alignment using this figure, coherent light is incident on the grating from two directions. and having a grating arranged substantially parallel to the interference fringes obtained by the interference of the two beams in the optical path of the two beams, guiding the light reflected or transmitted by the grating to the light detection means, A positioning method characterized in that the relative position between the interference fringes of the two beams of light and the grating is detected by measuring a change in the output of the photodetector, and the grating is aligned with the interference fringes. 3. The positioning method according to claim 2, wherein a pattern different from the period of the grating formed on the wafer is formed to overlap the grating.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58175353A JPS6066818A (en) | 1983-09-22 | 1983-09-22 | Position aligning method |
| US06/599,734 US4636077A (en) | 1983-04-15 | 1984-04-12 | Aligning exposure method |
| US07/296,721 USRE33669E (en) | 1983-04-15 | 1989-01-12 | Aligning exposure method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58175353A JPS6066818A (en) | 1983-09-22 | 1983-09-22 | Position aligning method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6066818A JPS6066818A (en) | 1985-04-17 |
| JPH0441484B2 true JPH0441484B2 (en) | 1992-07-08 |
Family
ID=15994583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58175353A Granted JPS6066818A (en) | 1983-04-15 | 1983-09-22 | Position aligning method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6066818A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5288115B2 (en) | 2008-12-10 | 2013-09-11 | ニチアス株式会社 | Catalytic converter and method for producing catalytic converter holding material |
| CN104570621B (en) * | 2015-01-14 | 2016-06-15 | 清华大学 | A kind of feedback regulation method of optical grating diffraction wave surface error in dual-beam exposure system |
| CN108761603B (en) * | 2018-05-22 | 2020-06-16 | 苏州大学 | Photoetching system for manufacturing parallel equidistant stripe holographic grating |
| CN108761602B (en) * | 2018-05-22 | 2020-06-16 | 苏州大学 | Adjusting method for auto-collimation of interference light path in holographic grating photoetching system |
-
1983
- 1983-09-22 JP JP58175353A patent/JPS6066818A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6066818A (en) | 1985-04-17 |
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