How Do You Draw a Circuit Smaller Than a Virus? · 怎麼畫出比病毒還小的電路？

Big idea · 一句話看懂

Chips are drawn with light. Light shines through a mask with the circuit pattern, lenses or mirrors shrink it onto a light-sensitive coating on the wafer, and the pattern is then etched in. This is repeated layer after layer, and the shorter the light's wavelength, the finer the lines.
晶片是用光畫出來的：光穿過畫好電路的光罩，鏡頭或反射鏡把圖案縮小，印在晶圓的感光膠上，再把圖案蝕刻出來。一層一層重複做；光的波長越短，畫得越細。

3D Model · 3D 模型

Drawing with Light 用光畫電路

Drag to turn the model, and scroll or pinch to zoom. In The machine, watch the light print one field after another across the wafer, and switch between DUV and EUV light. Then choose On the wafer to see a slice of the wafer go through the five steps that carve the pattern.
拖曳可以旋轉模型，滾輪或雙指可以縮放。在「曝光機」看光把晶圓一格一格印滿，並切換 DUV 和 EUV 兩種光；再選「晶圓上的步驟」，看晶圓剖面經過刻出圖案的五個步驟。

Drag to turn · 拖曳旋轉　Scroll or pinch to zoom · 滾輪／雙指縮放

This 3D model needs WebGL, which this browser does not support. The reading and the cards below still explain everything.
這個瀏覽器不支援 WebGL，無法顯示 3D 模型；下方的課文與卡片一樣能看懂。

Which light? · 用哪一種光？

Wavelength · 波長
Finest line · 最細的線
Focus with · 聚光
Light travels in · 光走在

Five steps on the wafer · 晶圓上的五步

Labels標示

Purple beam: ultraviolet light (really invisible)
紫色光束：紫外光（真實是看不見的）
Orange: photoresist, the light-sensitive coating
橘色：光阻，會感光的膜
Blue: the layer being patterned
藍色：要刻出圖案的薄膜
Silver: mirrors, chrome on the mask, the silicon wafer
銀色：反射鏡、光罩上的鉻、矽晶圓

A teaching diagram, not to scale. Ultraviolet light is invisible; it is drawn purple. A real machine is about the size of a bus, with many more mirrors and lenses than shown. In the wafer slice, the number of lines follows the finest line each light can print (about 57 nm for DUV and 16 nm for EUV), but the drawing is enlarged millions of times.
這是示意圖，不是真實比例。紫外光其實看不見，這裡畫成紫色。真的機器大約有一台公車那麼大，反射鏡和鏡頭也比圖上多得多。晶圓剖面裡的線條數，是照兩種光能印出的最細線寬（DUV 約 57 奈米、EUV 約 16 奈米）的比例畫的，但整張圖放大了好幾百萬倍。

Model drawn by My Culture Connect as a teaching diagram. Light sources, the 4× reduction, and the resolution formula follow ASML; the five steps follow Wikipedia's article on photolithography. · 模型由人師教育協會自繪示意；光源、縮小 4 倍與解析度公式依 ASML 的說明，五個步驟依維基百科的微影條目。

Reading · 英文閱讀

4

Unit 4: How Do You Draw a Circuit Smaller Than a Virus?

A transistor in a modern chip is far too small to draw with a pen, a laser, or even the sharpest needle. A flu virus is only about 80 to 120 nanometers across, and many lines in a chip are thinner than that. So how do engineers draw billions of them at once? They use light as a pen. The process is called photolithography, from Greek words meaning writing on stone with light.

現代晶片裡的電晶體，小到用筆、用雷射、甚至最尖的針都畫不出來。一個流感病毒只有約 80 到 120 奈米寬，而晶片裡很多線條比這還細。工程師怎麼一次畫出幾十億個？他們用光當筆。這個過程叫做「微影」（photolithography），英文字源於希臘文，意思是「用光在石頭上寫字」。

It works a bit like a stencil. First, the wafer is coated with photoresist, a thin film that changes when light hits it. The circuit pattern is drawn on a mask, a plate of quartz glass with chrome where light should be blocked. Light shines through the mask, and lenses shrink the pattern four times before it lands on the wafer.

它有點像用模板噴畫。首先，在晶圓上塗一層光阻：照到光就會改變的薄膜。電路圖案畫在「光罩」上，那是一片石英玻璃，要擋光的地方鍍上鉻。光穿過光罩，鏡頭把圖案縮小 4 倍，再落到晶圓上。

Next, the wafer is washed in a liquid called developer. In the most common kind of photoresist, the parts hit by light wash away, so the photoresist becomes a stencil with tiny openings. Chemicals or a plasma etch the layer underneath through the openings, and then the leftover photoresist is removed. The pattern from the mask is now carved into the chip.

接著，用一種叫「顯影液」的液體沖洗晶圓。最常見的光阻，照到光的部分會被洗掉，光阻就變成一張有細小開口的模板。再用化學藥劑或電漿，從開口把底下那層蝕刻掉，最後去掉剩下的光阻。光罩上的圖案就刻進晶片裡了。

One pattern is not enough. A chip is built up layer by layer: transistors at the bottom, then many layers of tiny metal wires above them. ASML, the Dutch company that makes the most advanced lithography machines, says a modern chip can need up to about 100 patterning steps. Every layer has to line up with the one below it almost perfectly.

一次圖案是不夠的。晶片是一層一層蓋起來的：最下面是電晶體，上面是好多層極細的金屬導線。製造最先進曝光機的荷蘭公司艾司摩爾（ASML）說，一顆現代晶片最多需要約 100 次圖案步驟。每一層都必須和下面那一層幾乎完美地對齊。

Why use such special light? The finest line light can draw depends on its wavelength. Many machines use deep ultraviolet (DUV) light with a wavelength of 193 nanometers. The newest use extreme ultraviolet (EUV) light at just 13.5 nanometers, more than 14 times shorter. EUV light is made by hitting tiny drops of tin with lasers, 50,000 drops every second. Even air absorbs it, so an EUV machine works in a vacuum and uses mirrors instead of lenses.

為什麼要用這麼特別的光？光能畫出多細的線，取決於它的波長。很多機器用波長 193 奈米的深紫外光（DUV）；最新的機器用只有 13.5 奈米的極紫外光（EUV），短了 14 倍以上。EUV 是用雷射打在小小的錫滴上產生的，每秒 5 萬滴。連空氣都會吸收它，所以 EUV 機器要在真空中工作，並且用反射鏡代替鏡頭。

A single speck of dust could ruin a pattern this small, so chips are made in cleanrooms. In the cleanest kind, ISO class 1, a cubic meter of air may hold no more than 10 particles bigger than 0.1 micrometers. Ordinary room air is around class 9, and each step up the scale allows about ten times more particles. The rooms where photoresist is handled are lit with yellow light, because blue and ultraviolet light would expose it by accident.

一粒灰塵就能毀掉這麼小的圖案，所以晶片要在無塵室裡做。最乾淨的 ISO 1 級無塵室，每立方公尺空氣裡大於 0.1 微米的微粒不能超過 10 顆。一般室內空氣大約是 9 級，而等級每往上一級，允許的微粒大約多 10 倍。處理光阻的房間用黃色的燈光，因為藍光和紫外光會不小心讓光阻感光。

Read aloud · 課文朗讀

Questions · 閱讀理解

What does the mask do?

It carries the circuit pattern. Light passes through its clear parts and is blocked by the chrome.

What happens to the most common kind of photoresist where light hits it?

Those parts wash away in the developer, leaving a stencil with tiny openings.

Why does an EUV machine use mirrors and work in a vacuum?

Glass and even air absorb EUV light, so it must travel in a vacuum and bounce off mirrors.

Words & Phrases · 生字及片語

pattern(n.)圖案；模式The tiles on the floor make a pretty pattern.地上的磁磚排成漂亮的圖案。stencil(n.)模板（鏤空版）We used a stencil to paint stars on the wall.我們用模板在牆上畫星星。lens(n.)鏡頭；透鏡A magnifying glass has a curved lens.放大鏡有一片彎曲的透鏡。mirror(n.)鏡子She checked her hair in the mirror.她在鏡子前看看頭髮。shrink(v.)縮小Wool sweaters can shrink in hot water.羊毛衣用熱水洗可能會縮水。layer(n.)層The cake has three layers of chocolate.這個蛋糕有三層巧克力。wavelength(n.)波長Red light has a longer wavelength than blue light.紅光的波長比藍光長。dust(n.)灰塵There was dust on the old books.舊書上積了一層灰塵。

Quick Check · 小測驗

1. What is photolithography?

2. Which light has the shorter wavelength?

3. In the most common photoresist, what happens to the parts hit by light?

4. Why are lithography rooms lit with yellow light?

5. How many times smaller is the pattern on the wafer than on the mask?

Make a Sun Print · 曬一張藍曬圖

Print with light on your screen 在螢幕上用光印圖案

This is how blueprints were made, and it works like a lithography machine without the lens. Choose a mask, leave the paper in the sun, then wash it. Try lifting the mask away from the paper.
藍圖（blueprint）就是這樣做的，原理像少了鏡頭的曝光機。選一張光罩，讓紙曬太陽，再用水沖洗。試試看把光罩拿離紙面。

1 · Choose a mask · 選一張光罩

2 · Time in the sun · 曬多久 3 · Gap between mask and paper · 光罩離紙多遠

The times are only examples. Real cyanotype paper needs anywhere from a few minutes to about 40 minutes, depending on the sun and the paper. The blur shows why a lithography machine must focus light so precisely: when shadows are fuzzy, thin lines run together.時間只是示例：真的藍曬紙要曬幾分鐘到大約 40 分鐘，看陽光和紙而定。模糊的效果說明了曝光機為什麼要把光聚得那麼準：影子一糊，細線就連在一起了。

Try It in the Model · 在模型裡試試

Four things to try 試試這四件事

ASML gives the finest line as about k1 × wavelength ÷ NA. NA describes how widely the lenses or mirrors gather light, and k1 is usually about 0.4. EUV's wavelength is 14 times shorter, but its mirrors gather light less widely, so its lines are about 3.5 times finer, not 14.
ASML 說，最細的線約等於 k1 × 波長 ÷ NA。NA 表示鏡頭或反射鏡收光的範圍有多大，k1 通常約 0.4。EUV 的波長短了 14 倍，但它的反射鏡收光範圍比較小，所以線條細了約 3.5 倍，而不是 14 倍。

A DUV machineDUV 曝光機

193 nm, glass lenses · 193 奈米，玻璃鏡頭

Light from a laser passes through the mask and a stack of lenses, and prints one field after another across the wafer.
雷射光穿過光罩和一疊鏡頭，把晶圓一格一格印滿。

An EUV machineEUV 曝光機

13.5 nm, mirrors in a vacuum · 13.5 奈米，真空裡的反射鏡

Laser pulses flash tin drops into glowing plasma, and the light bounces off mirrors and a reflective mask.
雷射把錫滴打成發光的電漿，光經過反射鏡和反射式光罩一路彈到晶圓上。

Five steps on the wafer晶圓上的五步

Coat, expose, develop, etch, strip · 塗、照、洗、刻、去

Watch a slice of the wafer as the mask's pattern is carved into the layer.
看晶圓剖面上，光罩的圖案怎麼刻進薄膜。

Finer lines更細的線

About 57 nm vs. 16 nm · 約 57 奈米對 16 奈米

Switch the light and compare the finished lines: EUV's are about three and a half times finer.
切換光源，比較刻好的線：EUV 的線大約細了三倍半。

Go Further · 延伸閱讀

Before and after this lesson 這一課的前後

Chips and Semiconductors · Lesson 3 · 晶片與半導體第三課How Does Sand Become a Chip?沙子怎麼變成晶片？Where the wafer comes from, and how many chips fit on it.晶圓從哪裡來，一片能放幾顆晶片。Go to the lesson · 前往這一課 →Chips and Semiconductors · Lesson 2 · 晶片與半導體第二課What Does a Transistor Do?電晶體在做什麼？The source, drain, and gate are exactly the shapes these patterns draw.源極、汲極、閘極，就是這些圖案畫出來的形狀。Go to the lesson · 前往這一課 →

Lithography by the Numbers · 微影的數字

Light, mirrors, and very clean air 光、反射鏡和非常乾淨的空氣

The numbers behind drawing with light.
用光畫電路背後的數字。

193 nmDUV light · 深紫外光的波長

Made by an argon fluoride laser.由氟化氬雷射產生。

13.5 nmEUV light · 極紫外光的波長

More than 14 times shorter than DUV.比 DUV 短 14 倍以上。

4×smaller on the wafer · 晶圓上縮小的倍數

The mask's pattern is four times larger than the chip's.光罩上的圖案是晶片上的 4 倍大。

50,000tin drops a second · 每秒的錫滴數

Each drop is hit by two laser pulses to make EUV light.每一滴都被雷射打兩次，才發出 EUV 光。

≈ 100patterning steps · 次圖案步驟

What a modern chip can need, according to ASML.ASML 說一顆現代晶片最多約需要這麼多次。

10particles per m³ · 顆微粒（每立方公尺）

The most allowed (0.1 µm or bigger) in the cleanest cleanrooms, ISO class 1.最乾淨的無塵室（ISO 1 級）允許的 0.1 微米以上微粒上限。

Lithography Stories · 微影的故事

A word, a blueprint, a giant machine, and yellow light 一個詞、一張藍圖、一台巨大的機器、一種黃色的光

Four stories about drawing with light.
關於「用光畫畫」的四個小故事。

1957 · Lathrop & Nall

Writing on stone with light用光在石頭上寫字

In 1957, Jay Lathrop and James Nall, working for the U.S. Army, patented a way to use light-sensitive coatings to pattern tiny metal strips for transistors. The word photolithography first appeared in print for this work in 1958. It comes from Greek: photo means light, litho means stone, and graphy means writing.
1957 年，替美國陸軍工作的拉斯羅普和納爾，取得一項專利：用感光塗料替電晶體做出細小的金屬條。1958 年，photolithography（微影）這個詞第一次為這項技術出現在刊物上。它來自希臘文：photo 是光、litho 是石頭、graphy 是書寫。

1842 · Blueprints · 藍圖

Pictures made by sunlight陽光印出來的圖

In 1842, the British scientist John Herschel published the cyanotype, a process that turns paper blue where light hits it. In 1843, Anna Atkins used it to make Photographs of British Algae, often called the first book illustrated with photographs. Architects and engineers later copied drawings this way, which is why we still say blueprint.
1842 年，英國科學家赫歇爾發表了「氰版照相」（藍曬）：紙張照到光的地方會變藍。1843 年，安娜．阿特金斯用它做出《英國藻類照片集》，常被稱為第一本用照片做插圖的書。後來建築師和工程師用這種方法複製圖紙，所以我們今天還說「藍圖」。

Veldhoven · ASML · 艾司摩爾

A machine the size of a bus像公車一樣大的機器

As of 2025, ASML, based in Veldhoven in the Netherlands, is the only company that makes EUV machines for chip production. Reuters describes one as about the size of a school bus and weighing about 150 tons, shipped in around 40 containers.
到 2025 年為止，總部在荷蘭費爾德霍溫的艾司摩爾（ASML），是世界上唯一生產晶片用 EUV 曝光機的公司。路透社形容一台大約像一輛校車那麼大、重約 150 公噸，要裝約 40 個貨櫃運送。

Yellow Light · 黃光

Why lithography rooms glow yellow微影區為什麼是黃色的

Photoresist reacts to blue and ultraviolet light, so the parts of a cleanroom where it is used are lit with yellow light that leaves it alone. One photoresist maker says light shorter than 500 nanometers must be filtered out.
光阻會對藍光和紫外光起反應，所以無塵室裡使用光阻的區域，都用不會讓它感光的黃色燈光。一家光阻廠商說，波長短於 500 奈米的光都要濾掉。

Myth vs. Fact · 常見迷思

Four things people get wrong 四個常見的誤會

✗ Myth · 迷思Chips are drawn line by line by a tiny robot pen or laser.晶片是用很小的機器筆或雷射一條一條畫出來的。

✓ Fact · 事實A whole field of the pattern is printed at once with light through a mask, a bit like taking a photograph.光穿過光罩，一次就印出一整格的圖案，有點像拍照。

✗ Myth · 迷思EUV light is just very bright purple light.EUV 就是很亮的紫色光。

✓ Fact · 事實EUV light is invisible, with a wavelength far shorter than any color we can see. Even air absorbs it.EUV 是看不見的光，波長比任何看得見的顏色都短得多，連空氣都會吸收它。

✗ Myth · 迷思The mask is the same size as the chip.光罩和晶片一樣大。

✓ Fact · 事實The pattern on the mask is four times larger. The machine's optics shrink it onto the wafer.光罩上的圖案是 4 倍大，由機器的光學系統縮小印到晶圓上。

✗ Myth · 迷思One trip through the machine makes a chip.晶片進曝光機一次就做好了。

✓ Fact · 事實A modern chip can need up to about 100 patterning steps, one layer on top of another.一顆現代晶片最多約要 100 次圖案步驟，一層疊一層。

Remember It · 記憶口訣

Drawing with light in a sentence 一句話記住用光畫電路

Coat, expose, develop, etch, strip塗、照、洗、刻、去

Five steps carve one pattern into one layer.
五個步驟，把一個圖案刻進一層。

Big mask, small chip光罩大、晶片小

The pattern shrinks four times on the way to the wafer.
圖案到晶圓上縮小 4 倍。

Shorter light, finer lines波長越短，線越細

193 nm DUV, 13.5 nm EUV.
DUV 193 奈米，EUV 13.5 奈米。

EUV: mirrors in a vacuumEUV：真空裡的反射鏡

Glass and air absorb it, so no lenses and no air.
玻璃和空氣都會吸收它，所以不用鏡頭、不要空氣。

Safety First · 安全提醒

Before you try anything 動手之前先讀

Never look directly at the sun, even through sunglasses or colored plastic.絕不要直視太陽，戴太陽眼鏡或透過有色塑膠片也不行。
Use ready-made sun-print paper. If older students mix cyanotype chemicals, an adult must supervise; wear gloves and goggles, and keep the chemicals away from strong acids.請用現成的藍曬紙。如果高年級學生要自己調藍曬藥劑，一定要有大人在旁，戴手套和護目鏡，並且遠離強酸。
Wash your hands after handling sun-print paper.碰過藍曬紙之後要洗手。
Use a flashlight, not a laser pointer, and never shine light into anyone's eyes.用手電筒，不要用雷射筆；也絕不要把光照向別人的眼睛。
An adult should handle the glass from a picture frame, or use a clear plastic sheet instead.相框的玻璃請大人拿；也可以改用透明塑膠片。

Classroom Activity 1 · 課堂活動一

Make a Sun Print 做一張藍曬圖

You need · 準備材料

Sun-print (cyanotype) paper from a craft or science shop美術或科學用品店買的藍曬紙
Flat objects such as leaves and paper clips, or a stencil cut from cardboard葉子、迴紋針這類扁平的東西，或用紙板剪的模板
A clear plastic sheet, and a tray of water一張透明塑膠片，和一盤清水

Steps · 步驟

Indoors, away from bright light, lay the paper blue side up and arrange your objects on it.在室內、避開強光，把藍曬紙藍色那面朝上，擺上你的東西。
Cover them with the clear sheet so they stay flat, then carry everything into the sun.蓋上透明塑膠片把東西壓平，再拿到太陽下。
Wait until the paper turns pale, following the time on the package. Then rinse it in water and let it dry.照包裝上的時間，等紙變淡，再放進水裡沖洗、晾乾。
Compare the edges. Which objects gave sharp edges, and which gave blurry ones? How is this like a lithography machine?比較邊緣：哪些東西印出的邊很清楚、哪些比較模糊？這和曝光機有什麼像的地方？

Try one object lifted a few centimeters above the paper. Its print will be fuzzier, just like an image that is out of focus.
試試看把一樣東西架高幾公分，它印出來會比較模糊，就像沒對準焦的影像。

Classroom Activity 2 · 課堂活動二

Shrink a Pattern with a Lens 用透鏡把圖案縮小