芯片是如何炼成的?

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连线图集】芯片是如何炼成的?

Lineker

于2010-10-21 19:52:44翻译 | 已有2843人浏览

芯片是如何炼成的?《连线》将带您前往应用材料公司位于加州圣克拉拉的梅登技术中心一探究竟

Tags:芯片 | 半导体 | 应用材料公司 | 硅晶圆 | 洁净室
If you wish to compose an e-mail, index a database of web pages, stream a kitten video in 720p or render an explosion at 60 frames per second, you must first build a computer.

如果你想写份邮件,检索一下网页的数据库,传输一段720p的小猫视频,或以60帧每秒的速度再现爆炸场面,首先必须得有台电脑。

And to build a computer, you must first design and fabricate the tiny processors that rapidly churn through the millions of discrete computational steps behind every one of those digital actions, taking a new step approximately 3 billion times per second.

若要构建一台电脑,你还得设计和制造出微小的处理器来,这些处理器必须能快速运算隐藏在数字行为背后海量的离散计算步骤,其运算速度要达到每秒30亿次。

To do all this, you are probably going to need chip-manufacturing machines from Applied Materials, one of the main suppliers of such equipment to the semiconductor industry.

其实归根结底,你还是需要去美国应用材料公司(Applied Materials)购置一套芯片加工设备,应用材料公司是半导体工业设备的主要供应商之一。

Applied's machines subject silicon wafers (such as the Intel wafer shown below) to incredibly intense vacuums, caustic chemical baths, high-energy plasmas, intense ultraviolet light, and more, taking the wafers through the hundreds of discrete manufacturing steps required to turn them into CPUs, memory chips and graphics processors.

应用材料公司的机器会对硅晶圆(如下图所展示的英特尔硅晶圆)进行一系列的处理:绝对真空,化学腐蚀,高能等离子体撞击和强烈的紫外线辐射等等,经过数百道分散的加工步骤以后,硅晶圆才会被打磨成CPU、存储芯片和图形处理器。

Because those processes aren't exactly friendly to humans, much of this work happens inside sealed chambers where robot arms move the wafers from one processing station to another. The machines themselves are housed within clean rooms whose scrubbed air (and bunny-suited employees) keep the risk of aerial contamination low: A single dust particle from your hair is all it takes to ruin a CPU that might sell for $500, so companies are eager to minimize how often that happens.

这些加工过程对人体的危害很大,因此大多数工作都在密封室中进行,机械手臂会把晶圆从一个加工区移到另一个加工区。机器本身也是被置于洁净室中,洁净室中的净化空气(以及全身裹得严严实实的员工)使空气污染降至最低。要知道,你头发上的一粒灰尘就足以将一块价值500美元的CPU变成废品,因此这些高科技公司都非常希望能将这种损失降到最低。

Wired/com recently toured Applied Materials' Maydan Technology Center, a state-of-the-art clean room in Santa Clara, California, where Applied develops and tests its machines.

《连线》最近探访了应用材料公司位于加州圣克拉拉(Santa Clara)的梅登技术中心(Maydan Technology Center),这是一家最先进的无尘中心,应用材料公司专门在此开发和测试其加工机器。

Its 39,000 square feet of ultraclean workspace equals about 81 yards of a football field, and is divided into three huge "ballrooms," each of which is crammed full of Applied's multimillion-dollar machines, alongside pipes, tubes, spare parts, tanks of caustic chemicals, Craftsman tool chests and huge racks of silicon wafers. To get inside, you must suit up in a bunny suit, with a face mask and goggles, two pairs of gloves, and shoe-covering footies. We couldn't even take a reporter's notebook inside: Instead, Applied's staff gave us a shrink-wrapped, specially sanitized clean-room notebook and clean-room pen to use.

3600平方米的超净工作区和一块足球场差不多大,被分割成三个大区,每块区域中都塞满了应用材料公司价值数百万的机器,机器旁边摆满了管道、管线、配件、装满腐蚀化学品的储罐、工具箱和架起的巨大硅晶圆。进入工作区以前,你必须穿上特制的工作服,戴上面罩和护目镜,双层手套和鞋套。甚至连记者用来记录的笔记本也不准带进去,公司的工作人员给我们每人发了一本洁净室专用的笔记本和钢笔,都是包在收缩膜中经过特殊净化过的。

It's not a manufacturing facility. Instead, this clean room simulates the fabs where Applied's machines will be used, enabling the company (and its customers) to test out new techniques and processes before putting them on the production line. As such, it provides a rare glimpse inside the world of cutting-edge semiconductor manufacturing.

这里并不是制造工厂,洁净室只是用来模拟机器的生产环境,在新工艺和工序投入实际生产线之前对其进行彻底检验。因此,它等同于为我们提供了一次极为难得的机会,去一睹尖端半导体的生产过程。

Top photo: Jon Snyder/Wired.com

上图来源:Jon Snyder/Wired.com

Bottom photo: Intel

图片来源:Intel

Photomask

光掩膜(Photomask)

The heart of chip manufacturing is lithography. It's like silkscreening, except instead of squeegeeing ink through a silk template onto a cotton T-shirt, you're shining ultraviolet light through a glass photomask onto a silicon substrate coated with an organic compound called photoresist.

芯片制造的核心工艺是光刻技术(lithography),它类似于丝网印刷,后者是将油墨通过丝模压到棉质T恤上,而光刻技术是利用透过玻璃光掩膜的紫外线辐射到包裹着光阻剂(photoresist)的硅衬底上。

Where the UV light shines through, it chemically weakens the photoresist, leaving a pattern on the surface of the silicon. Then the wafer is sent through a chemical bath that etches trenches into the exposed substrate, while leaving the areas covered by the photoresist untouched.

紫外线的照射会化学性弱化光阻剂,并在硅衬底的表面留下图案。晶圆再经过化学浸浴,利用腐蚀剂去蚀刻暴露出来的硅基质,同时那些覆盖有光阻剂的区域依然完好无损。

After removing the photoresist, other machines can fill those trenches with various materials, such as copper or aluminum, that comprise the components of the processor.

去除光阻剂以后,其他机器会在蚀刻痕迹中填入各种各样的材料,如铜或铝,它们是构成处理器的组件之一。

Shown here is a photomask, which bears the patterns that will be printed onto a wafer.

上图显示的即为一块光掩膜,它上面印的图案会被印到晶圆上。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

Deposit, Etch, Repeat

沉积,蚀刻,再重复

As a wafer is sent through the manufacturing facility, it can go through as many as 250 different steps. These processes include depositing films of various materials, then etching them to form transistors and copper wiring.

晶圆被送到制造区以后还需要进行250道不同工序的加工,这些工序包括不同材料的膜沉积,和将沉积膜蚀刻成晶体管和铜线的形式。

On the right is one of Applied Materials' Endura machines. The Endura platform is a modular, configurable system used to deposit metals and metal alloys on the wafer. It has been used in the manufacturing of almost every chip made in the past 20 years, according to Applied.

上图中的右图是一台应用材料公司生产的Endura机械系统。Endura平台是一种模块化的可配置系统,用来在晶圆上沉积金属和金属合金。用用材料公司的工作人员告诉我们,过去20年所出产的每块芯片都用到了Endura平台。

On the left is an Applied Tetra III advanced reticle-etch system. This system is used by virtually every maskmaker in the world for the development and production of 45-nanometer masks.

左图是一套Applied Tetra III高级掩膜蚀刻系统,如果掩膜板制造商要开发和生产45纳米的掩膜,就必须得使用这套设备。

Because it's developing and testing new manufacturing equipment, a huge amount of Applied's expenditures go towards research. In 2009, the company spent $934 million, or about 20 percent of its revenue, on R&D.

应用材料公司现在正在致力于开发和测试新型的制造设备,因此他们在相关研究上投入了巨额资金。2009年,公司在研发上的支出为9.34亿美元,占其销售收入的20%。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

The current state of the art for chip manufacturing is 30 nanometers, which means the average size of a chip component is just 30 billionths of a meter across.

目前最先进的芯片制造工艺为30纳米,这意味着芯片元件的平均尺寸为300亿分之一米。

Chip manufacturers are currently working on 22-nanometer designs, which are even smaller.

芯片制造商们现在致力于制造更小的22纳米芯片。

Adding to the challenge is the fact that some of these features are far deeper than they are wide -- in some cases, by a factor of 60 to 1. That means the etching systems have to be capable of creating extremely deep and narrow trenches in silicon, at the nanometer scale, with immense precision.

某些芯片元件的深度比其宽度要大得多——某些时候,深度与宽度之比达到了60比1,这种要求增加了加工的难度,它意味着蚀刻系统必须以极高的精度在硅晶圆上制造出极深极狭窄的纳米级沟道来。

The lithography room is lit with yellow light to avoid interference with the UV light used with the photomasks.

光刻室沐浴在黄色的灯光中,以避免对光掩膜中使用的紫外线造成干扰。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

Extreme Vacuum

极度真空

A technician works on the touchscreen interface of an Endura system.

上图中,一位技术员正在Endura系统的触摸屏界面上进行操作。

On the right is one of the large silver pumps used to create extreme vacuums inside the machine -- as low as 10-12 atmospheres. (By comparison, the air pressure at 200 kilometers [about 124 miles] above the Earth, where the Space Shuttle orbits, is about a hundred times thicker, at about 10-10 atmospheres.)

右边是一台大型的镀银泵,用于在机器内部创造真空——其真空度会低至10的负12次方个大气压(相比之下,地球上方200公里处,即航天飞机所在位置的真空度才达到10的负10次方个大气压)。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

No Metal Here

无金属过程

The silver metal device on the right side of this Centura machine is a batch loader, used to quickly depressurize a stack of wafers prior to feeding them into the machine for processing.

图中这台Centura机器右侧的银色金属装置是一台分批装载机,用来给堆积的晶圆迅速减压,再把它们送入机器进行加工。

The green "metal free tool" sign indicates that this machine is used in a part of the process prior to the addition of copper circuits. Copper is a contaminant that can mess up nonmetallic stages of the manufacturing process, so the machines that add copper need to be carefully segregated.

绿色的“非金属添加工具(metal free tool)”标志意味着硅晶圆必须得经过这台机器的处理以后,才能去添加铜质电路。铜是一种污染物,会对非金属加工过程造成混乱,因此用于添加铜质电路的机器需要被仔细的隔离。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

FOUP

前开式标准晶圆盒(FOUP)

Over the past several decades, the wafers upon which chips are made have steadily increased in size, enabling manufacturers to cram more chips on each disk. Since 2000, the industry standard has been 300 mm [about a foot in diameter].

过去几十年,随着晶圆尺寸的不断增加,芯片制造商们可以利用单片晶圆上制造出更多的芯片。2000年,半导体工业的晶圆标准被定为300毫米。

To simplify transportation and minimize the risk of contamination, fabs make use of "front-opening unified pods," or FOUPs. Each one holds 25 wafers in a sterile, clean environment.

为了简化运输和尽可能降低被污染的风险,芯片制造商利用“前开式标准晶圆盒”即所谓的FOUP来搬运晶圆。每个无尘超净的晶圆盒中可放置25块硅晶圆。

FOUPs can be docked onto the front of most of Applied's machines. The machines then suck the wafers inside and automatically process them one-by-one in quick succession.

FOUP可以对接在大多数应用材料机器系统的前端,机器可以将晶圆一片片的吸进去,自动进行加工。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

Automation and Storage

自动操作和存储

Because a front-opening unified pod full of silicon wafers can be heavy (around 20 pounds), automation is a key aspect of clean-room design.

装满硅晶圆的FOUP重量可达9公斤,因此自动化操作就成了洁净室设计的一项重要内容。

Applied's clean room has an overhead robotic monorail that transports FOUPs from place to place. In the sealed room shown here, up to 700 FOUPs (containing 17,500 wafers) can be stored until they're needed. Robot arms move the pods in and out of the racks on either side and onto an overhead monorail (not shown in this photo) that runs around the entire cleanroom.

应用材料公司的洁净室利用高架的机械单轨来搬用FOUP。在上图中的密封室中贮存着700个FOUP(共有17500块晶圆),需要使用时,机械手臂会将晶圆盒从架子的任意一端移出,放到高架的单轨(图中未显示)上,由单轨输送至目的地。

Another 2,800 FOUPs can be stored in the level below the main clean room.

另有2800个FOUP被存储在主洁净室的下方。

Every machine in a modern clean room is built around 300-mm wafers. The next generation of chips will be made on 450-mm wafers, enabling even larger economies of scale. But because companies will have to replace every single piece of equipment in order to work with 450-mm wafers, many are understandably reluctant to make the switch.

现代洁净室中的所有机器都是用来制造300毫米硅晶圆的。下一代的芯片将利用450毫米的硅晶圆进行生产,面积的扩大将会产生更多的规模效益,但同时也意味着芯片制造公司需要对所有的机器设备进行调整,因此很多公司不愿接受新标准也在情理之中。

When the transition does happen, it will be the end result of many, many long negotiations among companies like Applied Materials, Intel, AMD and others.

应用材料、因特尔、AMD和其他相关公司正在进行旷日持久的谈判磋商,一旦协商成功,这种转变将不可避免。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

Precision Manufacturing

精密制造业

Computer chips are only about the size of a fingernail, yet contain hundreds of millions of transistors, not to mention all the wiring needed to connect those transistors into a working machine and connect it to a motherboard and the rest of the world.

电脑芯片只有指甲盖般大小,却包含了数以百万计的晶体管,而将这些晶体管连接到其他工作单元、主板和电脑其他部分的线路更是不计其数。

They're made on circular silicon wafers about a foot in diameter, each of which can contain 200 separate but identical processors.

它们都集中在一块直径为30厘米的圆形硅晶圆上,每一块这样的晶圆可以被做成200块各自独立且完全相同的处理器。

And because contamination does happen occasionally, despite the purity of the clean room, manufacturers have to test every single one of those processors to make sure that its half-billion components, each of which is only about 30 to 45 nanometers wide, contain no manufacturing defects.

虽然洁净室异常干净,但污染还是避免不了,制造工人需要对每一块处理器进行测试,确保包含在其中的5亿个元件不会出现工艺缺陷,这些元件的尺寸只有30至45纳米。

It's no wonder that these types of machines can cost up to tens of millions of dollars (though most are single-digit millions). A full-blown fab, which might contain hundreds of such machines, can cost billions of dollars to build.

所以说,这些形态各异的机器每台都价值上千万美元(其实大多数都在几百万左右)也不足为奇了。一家成熟的芯片生产企业通常拥有上百台这样的机器,总价值将近几十亿美元。

And yet the factories pay for themselves. Worldwide semiconductor sales totaled $226.3 billion in 2009, and companies like Intel are among the most profitable corporations in the world.

然而,如此巨额的费用在那些财大气粗的企业看来不过尔尔。2009年,全世界半导体产业的销售额为2263亿美元,像因特尔这样的行业巨头一直跻身于世界上最赚钱的企业行列。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com

Mail Break

片刻休憩

The bunny-suited engineers and technicians who work in the clean room are responsible for setting up and monitoring the processes that go on inside the machines. But once a process is running, it's largely automated, which leaves downtime.

在洁净室中全副武装的工程师和技术人员负责设置和监视机器内部的加工过程。但是机器一旦开动,基本上是全自动化的,除非需要进行人工检修。

It took us about 10 minutes to get into or out of our multilayered bunny suits. And though experienced workers can do it in just a few minutes, it's enough of a hassle that once you're in the clean room, you generally want to stay in for awhile.

光是穿上或脱下这一套多层的防护服就花费了我们十分钟的时间,一般有经验的工人几分钟就搞定了。而在洁净室中,更是麻烦不断,一般人只能在里面呆一会儿。

As a result, workers use laptops inside the clean room to take care of other business while the machines are running. They analyze data, write reports and even check Gmail.

当机器在运行的时候,洁净室中的工作人员会利用笔记本干点别的,如分析数据、写报告和收发邮件什么的。

When they do, they're using chips that started out in a room much like this one.

其实他们电脑中所用的芯片当初也是从这样的车间被打磨出来的。

Photo: Jon Snyder/Wired.com

图片来源:Jon Snyder/Wired.com