Semiconductor

Semiconductor integrated circuit refers to a semiconductor integrated circuit device that has at least one circuit block on a semiconductor substrate.

Semiconductor integrated circuits are the interconnection of active components such as transistors and diodes, as well as passive components such as resistors and capacitors, according to a certain circuit, "integrated" on a single semiconductor chip to complete specific circuit or system functions.

On the semiconductor substrate, there are: multiple pads arranged at the edge of the circuit block and multiple wiring extending from the circuit block to the pads; The multiple pads are connected to the external leads of the semiconductor integrated circuit device, and the multiple wiring is used to connect the wiring from another circuit block on the main surface of the semiconductor substrate, forming a shape that can be connected to the wiring from the other circuit block.

Semiconductor integrated circuits are the core devices of electronic products, and the development of their industrial technology directly affects the level of development of the power industry. Overall, the technological progress of the semiconductor industry has to some extent driven the development of emerging industries, including the photovoltaic industry, semiconductor lighting industry, and flat panel display industry, promoting the improvement of the supply chain of upstream and downstream industries in the semiconductor integrated circuit industry, and optimizing the ecological environment to a certain extent. Therefore, strengthening the research and exploration of semiconductor integrated circuit industry technology has important practical significance.

Quality assurance measures

Process assurance

1) Raw material control. This includes the control of raw materials such as masks, chemical reagents, photoresists, and especially silicon materials. Control not only uses traditional single inspection methods, but also uses statistical process control (SPC) technology for key raw materials to ensure high quality levels and good quality consistency of raw materials.

2) Control of processing equipment. In addition to using advanced equipment for process processing, daily maintenance and preventive maintenance of the equipment should also be carried out, and key parameters of the equipment should be monitored. If necessary, an SPC control model for equipment parameters should be established for analysis and control.

3) Control of process processing. Including SPC control of key process parameters, process capability analysis, and 6 σ Design, etc., while establishing process inspection methods for key links in process processing, such as inspection of pinholes and cracks in the oxide layer, inspection of movable metal ions, and inspection of the stability of the metal layer. In addition, process assurance should also include training and assessment of operators, control of environmental cleanliness, and establishment of advanced production quality management information systems.

Design Assurance

1) Conventional reliability design techniques. Including redundancy design, derating design, sensitivity analysis, center value optimization design, etc.

2) Device design techniques for major failure modes. This includes designing device structures, geometric size parameters, and physical parameters reasonably for major failure modes such as hot carrier effects and latch effects.

3) Process design assurance for major failure modes. This includes adopting new process technologies and adjusting process parameters to improve the reliability of semiconductor integrated circuit chips.

4) Computer simulation technology for reliability of semiconductor integrated circuit chips. At the same time of circuit design, computer simulation analysis is conducted on the reliability of the circuit using circuit structure, layout and wiring, and reliability characteristic parameters as inputs. Based on the analysis results, it is possible to predict the reliability level of the circuit, determine the design rules that should be adopted in reliability design, and identify weak links in reliability in circuit and layout design schemes.

manufacturing process

Integrated circuit in approximately 5mm × On a 5mm sized silicon chip, the core part of a microcomputer has been integrated, containing over 10000 components. The typical manufacturing process of integrated circuits is shown in Figure 1. From Figure 1, it can be seen that an N+PN transistor, a resistor composed of a P-type diffusion region, and a capacitor composed of an N+P junction capacitor have been simultaneously manufactured on a silicon chip, and they are connected together using metal aluminum strips. In fact, on a commonly used silicon wafer with a diameter of 75mm (now developed to φ= 125mm~150mm) will have 3000000 such components, forming hundreds of circuits, subsystems, or systems. Through a series of processes such as oxidation, photolithography, diffusion or ion implantation, chemical vapor deposition evaporation or sputtering, all components of the entire circuit, their isolation, and metal interconnection patterns are simultaneously manufactured layer by layer on a single crystal chip, forming a three-dimensional network. And dozens or even hundreds of such silicon wafers can be processed simultaneously at once, so thousands of such circuits can be obtained in a batch. This high efficiency is precisely the technical and economic reason for the rapid development of integrated circuits.

This three-dimensional network can have various circuit and system functions, depending on the topology and process specifications of each layer. Under certain process specifications, the topology of each layer is mainly controlled by the topology, and the topology of each layer is determined by each photolithography mask. So the design of photolithography masks is a key factor in manufacturing integrated circuits.semiconductor testing It starts from the functional requirements of the system or circuit, designs according to actual possible process parameters, and completes the design and mask manufacturing with computer assistance.

After the completion of chip manufacturing, after testing, the chips on the silicon chip are marked one by one, and the chips that meet the performance requirements are packaged on the shell, forming a complete integrated circuit.

classification

If an integrated circuit is distinguished by the transistors that make up its circuit foundation, there are two types: bipolar integrated circuits and MOS integrated circuits. The former is mainly composed of bipolar junction planar transistors (as shown in Figure 2), while the latter is based on MOS field-effect transistors. Figure 3 shows the manufacturing process of a typical silicon gate N-channel MOS integrated circuit. Generally speaking, the advantage of bipolar integrated circuits is their fast speed, while the disadvantage is their low integration level and high power consumption; MOS integrated circuits, on the other hand, have the advantages of simple process, high integration, low power consumption, and slow speed due to the self isolation of MOS devices. In the recent development of leveraging their respective advantages and overcoming their own shortcomings,semiconductor failure analysis various new devices and circuit structures have emerged.

Integrated circuits can be divided into mathematical logic circuits based on gate circuits and linear circuits based on amplifiers according to their circuit functions. The latter develops slower than the former due to harmful interactions between the semiconductor substrate and the working components. Microwave integrated circuits for microwave applications and optical integrated circuits based on III-V compound semiconductor lasers and optical fiber conduits are also being developed.

In addition to silicon based materials, gallium arsenide is also an important material in semiconductor integrated circuits. Integrated circuits made from this material can operate at a speed of one order of magnitude higher than current silicon integrated circuits, and have broad development prospects.

From the perspective of the entire integrated circuit category, in addition to semiconductor integrated circuits, there are also thick film circuits and thin film circuits.

① Thick film circuits. Passive components and interconnecting wires are prepared using techniques such as screen printing and sintering on ceramic substrates, and then mixed and assembled with components such as transistors, diodes, integrated circuit chips, and discrete capacitors.

② Thin film circuits. It can be divided into full film and mixed film.aotomatic prober The so-called full film circuit refers to all active components, passive components, and interconnecting conductors required to form a complete circuit, all made using thin film technology on an insulating substrate. However, due to the poor performance and short lifespan of membrane transistors, they are difficult to apply in practice. So currently, the thin film circuit mainly refers to thin film hybrid circuits. It uses thin film processes such as vacuum evaporation and sputtering, as well as photolithography techniques, to manufacture resistors, capacitors, and interconnects on microcrystalline glass or ceramic substrates using materials such as metals, alloys, and oxides (the film thickness generally does not exceed 1 micrometer), and is then high-density mixed and assembled with one or more transistor devices and integrated circuit chips.

Compared with monolithic integrated circuits, thick film and thin film circuits have their own characteristics and complement each other. Thick film circuits are mainly used in high-power fields; Thin film circuits, on the other hand, mainly develop their application fields in high frequency and high precision. At present, the mutual penetration and combination of single-chip integrated circuit technology and hybrid integrated circuit technology have become an important direction for the development of large-scale and fully functional integrated circuit systems.