模拟集成电路 主要是指由电容、电阻、晶体管等组成的模拟电路集成在一起用来处理模拟信号的集成电路。有许多的模拟集成电路，如运算放大器、模拟乘法器、锁相环、电源管理芯片等。模拟集成电路的主要构成电路有：放大器、滤波器、反馈电路、基准源电路、开关电容电路等。模拟集成电路设计主要是通过有经验的设计师进行手动的电路调试，模拟而得到，与此相对应的数字集成电路设计大部分是通过使用硬件描述语言在EDA软件的控制下自动的综合产生。
1958年,杰克·基尔比在锗材料上用5个元件实现了一个简单的振荡器电路，成为世界上第一块集成电路。这一发明揭开了20世纪信息革命的序幕，标志着电子时代的到来。今天，随着以计算机和通信技术为代表的高科技产品在国防科技、工业生产和日常生活中越来越广泛的应用，以集成电路为代表的微电子产业也进入了一个前所未有的发展阶段。
集成电路(简称IC)按其功能、结构的不同，可以分为数字IC和模拟IC两大类。数字IC用来产生、放大和处理各种数字信号(指在时间和幅度上离散变化的信号。例如VCD、DVD重放的音频信号和视频信号)的电路。模拟IC是用来产生、放大和处理各种模拟信号(指幅度随时间连续变化的信号)的电路，是微电子技术的核心技术之一，能对电压或电流等模拟量进行采集、放大、比较、转换和调制。
我想问一下集成电路目前的现状，希望有专业人士不吝赐教，大致介绍一下目前比较前沿的发展情况。
What is an Integrated Circuit
Background
An integrated circuit, commonly referred to as an IC, is a microscopic array of electronic circuits and components that has been diffused or implanted onto the surface of a single crystal, or chip, of semiconducting material such as silicon It is called an integrated circuit because the components, circuits, and base material are all made together, or integrated, out of a single piece of silicon, as opposed to a discrete circuit in which the components are made separately from different materials and assembled later ICs range in complexity from simple logic modules and amplifiers to complete microcomputers containing millions of elements
The impact of integrated circuits on our lives has been enormous ICs have become the principal components of almost all electronic devices These miniature circuits have demonstrated low cost, high reliability, low power requirements, and high processing speeds compared to the vacuum tubes and transistors which preceded them Integrated circuit microcomputers are now used as controllers in equipment such as machine tools, vehicle operating systems, and other applications where hydraulic, pneumatic, or mechanical controls were previously used Because IC microcomputers are smaller and more versatile than previous control mechanisms, they allow the equipment to respond to a wider range of input and produce a wider range of output They can also be reprogrammed without having to redesign the control circuitry Integrated circuit microcomputers are so inexpensive they are even found in children's electronic toys
The first integrated circuits were created in the late 1950s in response to a demand from the military for miniaturized electronics to be used in missile control systems At the time, transistors and printed circuit boards were the state-of-the-art electronic technology Although transistors made many new electronic applications possible, engineers were still unable to make a small enough package for the large number of components and circuits required in complex devices like sophisticated control systems and handheld programmable calculators Several companies were in competition to produce a breakthrough in miniaturized electronics, and their development efforts were so close that there is some question as to which company actually produced the first IC In fact, when the integrated circuit was finally patented in 1959, the patent was awarded jointly to two individuals working separately at two different companies
After the invention of the IC in 1959, the number of components and circuits that could be incorporated into a single chip doubled every year for several years The first integrated circuits contained only up to a dozen components The process that produced these early ICs was known as small scale integration, or SSI By the mid-1960s, medium scale integration, MSI, produced ICs with hundreds of components This was followed by large scale integration techniques, or LSI, which produced ICs with thousands of components and made the first microcomputers possible
The first microcomputer chip, often called a microprocessor, was developed by Intel Corporation in 1969 It went into commercial production in 1971 as the Intel 4004 Intel introduced their 8088 chip in 1979, followed by the Intel 80286, 80386, and 80486 In the late 1980s and early 1990s, the designations 286, 386, and 486 were well known to computer users as reflecting increasing levels of computing power and speed Intel's Pentium chip is the latest in this series and reflects an even higher level
How Integrated Circuit
Components Are Formed
In an integrated circuit, electronic components such as resistors, capacitors, diodes, and transistors are formed directly onto the surface of a silicon crystal The process of manufacturing an integrated circuit will make more sense if one first understands some of the basics of how these components are formed
Even before the first IC was developed, it was known that common electronic components could be made from silicon The question was how to make them, and the connecting circuits, from the same piece of silicon The solution was to alter, or dope, the chemical composition of tiny areas on the silicon crystal surface by adding other chemicals, called dopants Some dopants bond with the silicon to produce regions where the dopant atoms have one electron they can give up These are called N regions Other dopants bond with the silicon to produce regions where the dopant atoms have room to take one electron These are called P regions When a P region touches an N region, the boundary between them is referred to as a PN junction This boundary is only 0000004 inches (00001 cm) wide, but is crucial to the operation of integrated circuit components
Within a PN junction, the atoms of the two regions bond in such a manner as to create a third region, called a depletion region, in which the P dopant atoms capture all the N dopant extra electrons, thus depleting them One of the phenomena that results is that a positive voltage applied to the P region can cause an electrical current to flow through the junction into the N region, but a similar positive voltage applied to the N region will result in little or no current flowing through the junction back into the P region This ability of a PN junction to either conduct or insulate depending on which side the voltage is applied can be used to form integrated circuit components that direct and control current flows in the same manner as diodes and transistors A diode, for example, is simply a single PN junction By altering the amount and types of dopants and changing the shapes and relative placements of P and N regions, integrated circuit components that emulate the functions of resistors and capacitors can be also be formed
Design
Some integrated circuits can be considered standard, off-the-shelf items once designed, there is no further design work required Examples of standard ICs would include voltage regulators, amplifiers, analog switches, and analog-to-digital or digital-to-analog converters These ICs are usually sold to other companies who incorporate them into printed circuit boards for various electronic products
Other integrated circuits are unique and require extensive design work An example would be a new microprocessor for computers This design work may require research and development of new materials and new manufacturing techniques to achieve the final design
Raw Materials
Pure silicon is the basis for most integrated circuits It provides the base, or substrate for the entire chip and is chemically doped to provide the N and P regions that make up the integrated circuit components The silicon must be so pure that only one out of every ten billion atoms can be an impurity This would be the equivalent of one grain of sugar in ten buckets of sand Silicon dioxide is used as an insulator and as a dielectric material in IC capacitors
Typical N-type dopants include phosphorus and arsenic Boron and gallium are typical P-type dopants Aluminum is commonly used as a connector between the various IC components The thin wire leads from the integrated circuit chip to its mounting package may be aluminum or gold The mounting package itself may be made from ceramic or plastic materials
The Manufacturing
Process
Hundreds of integrated circuits are made at the same time on a single, thin slice of silicon and are then cut apart into individual IC chips The manufacturing process takes place in a tightly controlled environment known as a clean room where the air is filtered to remove foreign particles The few equipment operators in the room wear lint-free garments, gloves, and coverings for their heads and feet Since some IC components are sensitive to certain frequencies of light, even the light sources are filtered Although manufacturing processes may vary depending on the integrated circuit being made, the following process is typical
Preparing the silicon wafer
A cylindrical ingot of silicon about 15 to 40 inches (38 to 102 cm) in diameter is held vertically inside a vacuum chamber with a high-temperature heating coil encircling it Starting at the top of the cylinder, the silicon is heated to its melting point of about 2550°F (1400°C) To avoid contamination, the heated region is contained only by the surface tension of the molten silicon As the region melts, any impurities in the silicon become mobile The heating coil is slowly moved down the length of the cylinder, and the impurities are carried along with the melted region When the heating coil reaches the bottom, almost all of the impurities have been swept along and are concentrated there The bottom is then sliced off, leaving a cylindrical ingot of purified silicon
A thin, round wafer of silicon is cut off the ingot using a precise cutting machine called a wafer slicer Each slice is about 001 to 0025 inches (0004 to 001 cm) thick The surface on which the integrated circuits are to be formed is polished
The surfaces of the wafer are coated with a layer of silicon dioxide to form an insulating base and to prevent any oxidation of the silicon which would cause impurities The silicon dioxide is formed by subjecting the wafer to superheated steam at about 1830°F (1000°C) under several atmospheres of pressure to allow the oxygen in the water vapor to react with the silicon Controlling the temperature and length of exposure controls the thickness of the silicon dioxide layer
Masking
The complex and interconnected design of the circuits and components is prepared in a process similar to that used to make printed circuit boards For ICs, however, the dimensions are much smaller and there are many layers superimposed on top of each other The design of each layer is prepared on a computer-aided drafting machine, and the image is made into a mask which will be optically reduced and transferred to the surface of the wafer The mask is opaque in certain areas and clear in others It has the images for all of the several hundred integrated circuits to be formed on the wafer
A drop of photoresist material is placed in the center of the silicon wafer, and the wafer is spun rapidly to distribute the photoresist over the entire surface The photoresist is then baked to remove the solvent
The coated wafer is then placed under the first layer mask and irradiated with light Because the spaces between circuits and components are so small, ultraviolet light with a very short wavelength is used to squeeze through the tiny clear areas on the mask Beams of electrons or x-rays are also sometimes used to irradiate the photoresist
The mask is removed and portions of the photoresist are dissolved If a positive photoresist was used, then the areas that were irradiated will be dissolved If a negative photoresist was used, then the areas that were irradiated will remain The uncovered areas are then either chemically etched to open up a layer or are subjected to chemical doping to create a layer of P or N regions
Doping—Atomic diffusion
One method of adding dopants to create a layer of P or N regions is atomic diffusion In this method a batch of wafers is placed in an oven made of a quartz tube surrounded by a heating element The wafers are heated to an operating temperature of about 1500-2200°F (816-1205°C), and the dopant chemical is carried in on an inert gas As the dopant and gas pass over the wafers, the dopant is deposited on the hot surfaces left exposed by the masking process This method is good for doping relatively large areas, but is not accurate for smaller areas There are also some problems with the repeated use of high temperatures as successive layers are added
Doping—lon implantation
The second method to add dopants is ion implantation In this method a dopant gas, like phosphine or boron trichloride, is ionized to provide a beam of high-energy dopant ions which are fired at specific regions of the wafer The ions penetrate the wafer and remain implanted The depth of penetration can be controlled by altering the beam energy, and the amount of dopant can be controlled by altering the beam current and time of exposure Schematically, the whole process resembles firing a beam in a bent cathode-ray tube This method is so precise, it does not require masking—it just points and shoots the dopant where it is needed However it is much slower than the atomic diffusion process
Making successive layers
The process of masking and etching or doping is repeated for each successive layer depending on the doping process used until all of the integrated circuit chips are complete Sometimes a layer of silicon dioxide is laid down to provide an insulator between layers or components This is done through a process known as chemical vapor deposition, in which the wafer's surface is heated to about 752°F (400°C), and a reaction between the gases silane and oxygen deposits a layer of silicon dioxide A final silicon dioxide layer seals the surface, a final etching opens up contact points, and a layer of aluminum is deposited to make the contact pads At this point, the individual ICs are tested for electrical function
Making individual ICs
The thin wafer is like a piece of glass The hundreds of individual chips are separated by scoring a crosshatch of lines with a fine diamond cutter and then putting the wafer under stress to cause each chip to separate Those ICs that failed the electrical test are discarded Inspection under a microscope reveals other ICs that were damaged by the separation process, and these are also discarded
The good ICs are individually bonded into their mounting package and the thin wire leads are connected by either ultrasonic bonding or thermocompression The mounting package is marked with identifying part numbers and other information
The completed integrated circuits are sealed in anti-static plastic bags to be stored or shipped to the end user
Quality Control
Despite the controlled environment and use of precision tools, a high number of integrated circuit chips are rejected Although the percentage of reject chips has steadily dropped over the years, the task of making an interwoven lattice of microscopic circuits and components is still difficult, and a certain amount of rejects are inevitable
Hazardous Materials and
Recycling
The dopants gallium and arsenic, among others, are toxic substances and their storage, use, and disposal must be tightly controlled
Because integrated circuit chips are so versatile, a significant recycling industry has sprung up Many ICs and other electronic components are removed from otherwise obsolete equipment, tested, and resold for use in other devices
The Future
It is difficult to tell with any certainty what the future holds for the integrated circuit Changes in technology since the device's invention have been rapid, but evolutionary Many changes have been made in the architecture, or circuit layout, on a chip, but the integrated circuit still remains a silicon-based design
The next major leap in the advancement of electronic devices, if such a leap is to come, may involve an entirely new circuit technology Better devices than the very best microprocessor have always been known to be possible The human brain, for example, processes information much more efficiently than any computer, and some futurists have speculated that the next generation of processor circuits will be biological, rather than mineral At this point, such matters are the stuff of fiction There are no immediate signs that the integrated circuit is in any danger of extinction
专用集成电路设计的内容简介
目前我国人工智能、汽车电子、物联网、5G等现代科技行业的发展都离不开集成电路的支持，换言之，集成电路是目前我国科技发展的核心零部件，因此我国政府高度重视集成电路的发展，出台了多项政策支持集成电路行业。尤其是在经济发达的长三角和泛珠三角区域，上海、广东等城市拥有强大的经济和人才优势，在“十四五”期间形成了集成电路集群化发展的趋势。
1、集成电路渗透到我国各个行业
集成电路是我国科技发展的重要组成部分，也是我国各行各业实现智能化、数字化的基础。目前我国集成电路渗透到我国各个行业，例如工业机器人、5G网络建设、汽车电子以及计算机等重要科技领域，可以说集成电路是我国科技发展的基石，集成电路技术发展到位，我国才能够在科技领域不受制于人。
2、我国集成电路行业依赖进口较为严重
目前集成电路已渗透到我国各个行业，对于我国科技、工业等领域发展显得尤为重要，但因集成电路行业具有较高的技术壁垒，我国目前尚未完全突破技术壁垒，因此在7nm等精度较高的集成电路领域，我国仍需要进口。换言之，在关键技术领域，我国集成电路依赖进口较为严重。
2017-2020年，我集成电路进出口数量均呈现上升趋势，且进出口逆差也在不断扩大。根据海关总署数据显示，2020年中国共进口集成电路5431亿个，较2019年增加985亿个;出口集成电路2596亿个，较2019年增加411个，贸易逆差为2835亿个。2021年1-2月，我国累计进口集成电路963亿个;出口集成电路468亿个，贸易逆差为495亿个。
3、多项规划指明集成电路发展方向
在《中国制造2025》中针对集成电路产业的市场规模、产能规模等提出了具体的量化目标，同时在全国两会发布的《中华人民共和国国民经济和社会发展第十四个五年规划和2035年远景目标纲要》中也提到在事关国家安全和发展全局的基础核心领域，制定实施战略性科学计划和科学工程。瞄准人工智能、量子信息、集成电路等前沿领域，实施一批具有前瞻性、战略性的国家重大科技项目。
从国家急迫需要和长远需求出发，集中优势资源攻关关键元器件零部件和基础材料等领域关键核心技术。支持北京、上海、粤港澳大湾区形成国际科技创新中心，建设北京怀柔、上海张江、大湾区、安徽合肥综合性国家科学中心，支持有条件的地方建设区域科技创新中心。
3、政策规划下我国集成电路市场规模不断提升
在我国政策的促进下，我国集成电路行业主要代表企业不断突破技术壁垒，促进我国集成电路行业的发展，其中，中芯国际已能够生产n+1 nm的集成电路，虽不能完全替代7nm的芯片，但也能在短时间内解决我国机场电路短缺的问题。
根据中国半导体行业协会数据显示，2015-2020年我国集成电路市场规模呈逐年增加趋势。2020年我国集成电路市场规模为8848亿元，较2019年增加1700%。
4、“十四五”期间各省份出台规划促进集成电路发展
目前长三角地区的安徽省、江苏省、上海市，泛珠三角地区的江西省、福建省、广东省、四川省均对“十四五”期间，集成电路的发展做出了明确的目标规划，形成了较为明确的集群化发展，除此之外，湖北省、重庆市以及山西省也针对“十四五”期间集成电路的发展做出了明确的目标规划。
综合来看，集成电路行业的发展对于我国工业智能化、5G网络、汽车电子、计算机等关键领域的发展起着至关重要的作用，但目前由于我国尚未完全突破集成电路的技术壁垒，到至我国对集成电路的进口依赖较为明显，未来在《中国智造2025》以及《中华人民共和国国民经济和社会发展第十四个五年规划和2035年远景目标纲要》的支持下，我国集成电路的发展会越来越好。
除国家层面外，我国经济较为发达的省份也在不停的摸索集成电路的发展，目前在长三角和泛珠三角地区已形成了集成电路发展的集群效应。
—— 更多数据请参考前瞻产业研究院《中国集成电路行业市场需求预测与投资战略规划分析报告》
定制集成电路的简介
专用集成电路(ASIC)是电子设备的核心，是信息技术工业领域自主知识产权的重要象征。专用集成电路设计是电子工程师必须掌握的技术之一。《专用集成电路设计》以使工程技术人员熟练掌握专用集成电路，主要是数字专用集成电路设计技术为目标，较详细介绍了专用集成电路的设计流程、设计工具与设计方法。
《专用集成电路设计》可作为信息技术及相关领域研究生或本科生教材，也可作为相关工程技术人员的参考书。
集成电路各元件介绍
按用户需求而设计制作的集成电路(ASIC)应运而生，按制作方式可分为全定制集成电路和半定制集成电路。
全定制集成电路是按照预期功能和技术指标而专门设计制成的集成电路，制造周期长、成本高，制成后不易修改，但性能比较理想，芯片面积小，集成度高。
半定制集成电路的设计分为基于标准单元的设计方法和基于门阵列的设计方法。基于标准单元的设计方法是：将预先设计好的、称为标准单元的逻辑单元，如与门、或门、多路开关、触发器等，按照某种特定的规则排列，与预先设计好的大型单元一起组成ASIC。基于标准单元的ASIC又称为CBIC(Cell based IC)；基于门阵列的设计方法是在预先制定的具有晶体管阵列的基片或母片上通过掩膜互连的方法完成专用集成电路设计。半定制集成电路制法很多，其中的门阵列法是先将标准电路单元如门电路加工成半成品（门阵列、门海等），然后按用户的技术要求进行设计，将芯片上的各标准电路单元连成各种功能电路，进而连成所要的大规模集成电路。采用此法，从预制的半成品母片出发，借助计算机辅助设计系统 ，只须完成一 、两块连线用的掩膜版再进行后工序加工，即可得到预期的电路。。因此研制周期大大缩短 、成本降低、修改设计方便，宜于大批量生产。缺点是芯片面积利用率低，性能不如全定制集成电路 。
双极型集成电路
bipolar integrated circuit
以通常的NPN或PNP型双极型晶体管为基础的单片集成电路。它是1958年世界上最早制成的集成电路。双极型集成电路主要以硅材料为衬底，在平面工艺基础上采用埋层工艺和隔离技术，以双极型晶体管为基础元件。按功能可分为数字集成电路和模拟集成电路两类。在数字集成电路的发展过程中，曾出现了多种不同类型的电路形式，典型的双极型数字集成电路主要有晶体管-晶体管逻辑电路(TTL)，发射极耦合逻辑电路(ECL)，集成注入逻辑电路(I2L)。TTL电路形式发展较早，工艺比较成熟。ECL电路速度快，但功耗大。I2L电路速度较慢，但集成密度高。
同金属-氧化物-半导体集成电路相比，双极型集成电路速度快，广泛地应用于模拟集成电路和数字集成电路。
在半导体内，多数载流子和少数载流子两种极性的载流子（空穴和电子）都参与有源元件的导电，如通常的NPN或PNP双极型晶体管。以这类晶体管为基础的单片集成电路，称为双极型集成电路。
双极型集成电路是最早制成集成化的电路，出现于1958年。双极型集成电路主要以硅材料为衬底，在平面工艺基础上采用埋层工艺和隔离技术，以双极型晶体管为基础元件。它包括数字集成电路和线性集成电路两类。
发展简况双极型集成电路是在硅平面晶体管的基础上发展起来的，最早的是双极型数字逻辑集成电路。在数字逻辑集成电路的发展过程中，曾出现过多种不同类型的电路形式。常见的双极型集成电路可分类如下。
DCTL电路是第一种双极型数字逻辑集成电路，因存在严重的“抢电流”问题(见电阻-晶体管逻辑电路)而不实用。RTL电路是第一种有实用价值的双极型集成电路。早期的数字逻辑系统曾采用过 RTL电路，后因基极输入回路上有电阻存在，限制了开关速度。此外,RTL逻辑电路的抗干扰的性能较差，使用时负载又不能多，因而被淘汰。电阻-电容-晶体管逻辑电路（RCTL）是为了改善RTL电路的开关速度而提出来的，即在RTL电路的电阻上并接电容。实际上 RCTL电路也未得到发展。DTL电路是继 RTL电路之后为提高逻辑电路抗干扰能力而提出来的。DTL电路在线路上采用了电平位移二极管,抗干扰能力可用电平位移二极管的个数来调节。常用的 DTL电路的电平位移二极管，是用两个硅二极管串接而成，其抗干扰能力可提高到14伏左右（见二极管-晶体管逻辑电路）。HTL电路是在 DTL电路的基础上派生出来的。HTL电路采用反接的齐纳二极管代替DTL电路的电平位移二极管,使电路的阈值提高到约74伏左右(见高阈值逻辑电路)。可变阈值逻辑电路(VTL)也是DTL电路系列中的另一种变形电路。阈值逻辑电路(TLC)是 HTL和VTL逻辑电路的总称。TTL逻辑电路是在DTL逻辑电路基础上演变而来，于1962年研制成功。为了提高开关速度和降低电路功耗,TTL电路在线路结构上经历了三代电路形式的改进(见晶体管-晶体管逻辑电路)。
以上均属饱和型电路。在进一步探索提高饱和型电路开关速度的同时，发现晶体管多余载流子的存储效应是一个极重要的障碍。存储现象实质上是电路在开关转换过程中由多余载流子所引起。要提高电路开关速度,除了减少晶体管PN结电容，或者设法缩短多余载流子的寿命以外，就得减少和消除晶体管内载流子存储现象。60年代末和70年代初，人们开始在集成电路中利用熟知的肖特基效应。在TTL电路上制备肖特基势垒二极管,把它并接在原有晶体管的基极和集电极上，使晶体管开关时间缩短到1纳秒左右；带肖特基势垒二极管箝位的TTL门电路的平均传输延迟时间达2～4纳秒。
肖特基势垒二极管-晶体管-晶体管逻辑电路(STTL)属于第三代 TTL电路。它在线路上采用了肖特基势垒二极管箝位方法，使晶体管处于临界饱和状态，从而消除和避免了载流子存储效应。与此同时,在TTL电路与非门输出级倒相器的基极引入晶体管分流器，可以改善与非门特性。三极管带有肖特基势垒二极管，可避免进入饱和区，具有高速性能；输出管加上分流器，可保持输出级倒相的抗饱和程度。这类双极型集成电路，已不再属于饱和型集成电路，而属于另一类开关速度快得多的抗饱和型集成电路。
发射极耦合逻辑电路(ECL)是电流型逻辑电路(CML)。这是一种电流开关电路, 电路的晶体管工作在非饱和状态,电路的开关速度比通常TTL电路又快几倍。ECL逻辑电路把电路开关速度提高到 1纳秒左右，大大超过 TTL和STTL电路。ECL电路的出现,使双极型集成电路进入超高速电路范围。
集成注入逻辑电路 (I2L)又称合并晶体管逻辑电路(MTL)，是70年代研制成的。在双极型集成电路中，I2L电路的集成密度是最高的。
三层结构逻辑电路(3TL)是1976年中国在I2L电路的基础上改进而成,因有三层结构而得名。3TL逻辑电路采用NPN管为电流源，输出管采用金属做集电极(PNM)，不同于I2L结构。
多元逻辑电路(DYL)和双层逻辑电路(DLL)，是1978年中国研制成功的新型逻辑电路。DYL逻辑电路线性与或门,能同时实现开关逻辑和线性逻辑处理功能。DLL电路是通过ECL和TTL逻辑电路双信息内部变换来实现电路逻辑功能的。
此外，在双极型集成电路发展过程中，还有许多其他型式的电路。例如,发射极功能逻辑电路(EFL)、互补晶体管逻辑电路(CTL)、抗辐照互补恒流逻辑电路(C3L)、电流参差逻辑电路(CHL)、三态逻辑电路(TSL)和非阈值逻辑电路(NTL)等。
特点和原理双极型集成电路的制造工艺，是在平面工艺基础上发展起来的。与制造单个双极型晶体管的平面工艺相比，具有若干工艺上的特点。
① 双极型集成电路中各元件之间需要进行电隔离。集成电路的制造，先是把硅片划分成一定数目的相互隔离的隔离区；然后在各隔离区内制作晶体管和电阻等元件。在常规工艺中大多采用PN结隔离，即用反向PN结达到元件之间相互绝缘的目的。除PN结隔离以外，有时也采用介质隔离或两者混合隔离法（见隔离技术）。
② 双极型集成电路中需要增添隐埋层。通常，双极型集成电路中晶体管的集电极，必须从底层向上引出连接点，因而增加了集电极串连电阻，这不利于电路性能。为了减小集电极串连电阻，制作晶体管时在集电极下边先扩散一层隐埋层，为集电极提供电流低阻通道和减小集电极的串联电阻。隐埋层，简称埋层，是隐埋在硅片体内的高掺杂低电阻区。埋层在制作集成电路之前预先“埋置”在晶片体内。其工艺过程是：在 P型硅片上，在预计制作集电极的正下方某一区域里先扩散一层高浓度施主杂质即N+区;而后在其上再外延生长一层N型硅单晶层。于是，N型外延层将N+区隐埋在下面,再在这一外延层上制作晶体管。
③ 双极型集成电路通常采用扩散电阻。电路中按电阻阻值大小选择制备电阻的工艺，大多数是利用晶体管基区P型扩散的同时，制作每方约 150～200欧·厘米的P型扩散电阻。但是,扩散电阻存在阻值误差大、温度系数高和有寄生效应等缺点。除采用扩散电阻外，有时也采用硅单晶体电阻。
④ 双极型集成电路元件间需要互连线，通常为金属铝薄层互连线。单层互连布线时难以避免交叉的位置，必要时可采用浓磷扩散低阻区，简称磷桥连接法。
⑤ 双极型集成电路存在寄生效应。双极型集成电路的纵向NPN晶体管，比分立晶体管多一个P型衬底层和一个PN结。它是三结四层结构。增加的衬底层是所有元件的公共衬底，增加的一个PN结是隔离结(包括衬底结)。双极型集成电路因是三结四层结构而会产生特有的寄生效应：无源寄生效应、扩散电阻的寄生电容和有源寄生效应。隔离电容是集电极N型区与隔离槽或衬底P型区形成的PN结产生的电容。隔离和衬底接最低电位，所以这个电容就是集电极对地的寄生电容。扩散电阻的寄生电容是扩散电阻P型区与集电极外延层N型区产生的PN结电容，也属无源寄生效应。这一PN结电容总是处于反偏置工作状态。有源寄生效应即 PNP寄生晶体管。在电路中，NPN晶体管的基区、集电区（外延层）和衬底构成PNP寄生晶体管。在通常情况下，因PN结隔离，外延层和衬底之间总是反向偏置。只有当电路工作时,NPN管的集电结正偏，寄生PNP管才进入有源区。
工艺制备（见彩图）是利用PN结隔离技术制备双极型集成电路倒相器的工艺流程，图中包括一个NPN晶体管和一个负载电阻R。原始材料是直径为75～150毫米掺P型杂质的硅单晶棒，电阻率ρ=10欧·厘米左右。其工艺流程是：先经过切片、研磨和抛光等工艺(是硅片制备工艺)制备成厚度约300～500微米的圆形硅片作为衬底，然后进行外延生长、氧化、光刻、扩散、蒸发、压焊和多次硅片清洗，最后进行表面钝化和成品封装。
制作双极型集成电路芯片需要经过 5次氧化，对氧化硅 (SiO2)薄层进行5次光刻，刻蚀出供扩散掺杂用的图形窗口。最后还经过两次光刻，刻蚀出金属铝互连布线和钝化后用于压焊点的窗口。因此，整套双极型集成电路掩模版共有 7块。即使通常省去钝化工艺，也需要进行6次光刻，需要6块掩模版。
