The design phase of an integrated circuit can be divided into different sections such as architectural design, logic functional design, circuit design, physical design, etc.
Electronic Design Automation (EDA) and Computer-Aided Design (CAD) tools are used to design integrated circuits.
In monolithic technology, all the components are embedded into a single semiconductor substrate and interconnections are also fabricated on it.
As the integrated circuit function differs, the design of the chip is also different; however, the IC fabrication process flow is almost the same
Integrated circuits (IC) are extensively used in computers, smartphones, automobiles, communication systems, household electronic appliances, etc. Depending on the nature of the application, the type of IC varies.
If planning to process continuous signals, then analog ICs are required. If it's a digital IC, it handles binary information. There are mixed-signal ICs as well, which perform signal processing of both analog and digital signals. As the integrated circuit function differs, the design of the chip is also different; however, the IC fabrication process flow is almost the same.
Integrated Circuit Design
The integrated circuit is an important part of microelectronics. The integrated circuit embeds all the necessary components to perform an electronic operation within a small package. The basic building blocks of the integrated circuit, such as the resistors, capacitors, diodes, transistors, etc., reside inside the package developed on the semiconductor substrate surface.
Depending on the application, the internal structure and the number of transistors and other related blocks differ. The integrated circuit design is complex, especially as the number of transistors and other elements increases.
Integrated Circuit Manufacturing Phases
1. System Specification or User Requirements
The objective of fabricating the IC is formulated and the related system specification or requirements are added.
2. Design Phase
Can be divided into different sections, such as architectural design, logic functional design, circuit design, physical design, etc.
3. Verification Phase
The designed integrated circuit is verified and checked for its match with the system specification.
The integrated circuit is physically realized at this fabrication stage. Circuits only get to this stage if they pass the verification stage.
3. Packaging and Testing
The fabricated IC is properly packed into a particular packaging style before the post-fabrication testing and analysis are performed.
Integrated Circuit Design Flow
- Integrated circuit design starts with the creation of a schematic. The schematic can be used for symbol creation.
- Various simulations can be performed on the schematic for DC, AC, and transient analysis.
- The circuit operation verification can be done at this stage.
- Once the verification is over, the layout can be developed.
- The geometrics and relative location of each mask layer can be detailed for fabrication.
The circuit layout and schematic should match. The mask layout of the integrated circuit should adhere to design rules to minimize fabrication defects. The problems encountered during the design rule check are red flags for the designer to return back to the designing phase. When all the design rule checks are obeyed, the IC can be taken for fabrication.
IC Fabrication Technology
The integrated circuit can be fabricated using one of the technologies discussed below.
Monolithic Technology - In monolithic technology, all the components are embedded into a single semiconductor substrate, and interconnections are also fabricated on it. Large-scale fabrication prefers monolithic technology, as the fabrication cost is less, but the ICs are reliable.
Hybrid Technology - In hybrid technology, the components are developed separately and attached to a ceramic substance. The metallization patterns or wires are used for establishing interconnections.
IC Fabrication Process Flow Chart
The IC fabrication process flowchart gives the different steps involved in the fabrication process. The base material for the IC fabrication is a semiconductor material, mostly a silicon wafer. The fabrication stage of the IC is given below.
The semiconductor wafer is baked and hardened after applying a photo-resisting liquid layer. This is the process of lithography in IC fabrication.
Detaching the unnecessary materials from the wafer.
Deposition or Doping
Chemical vapor and physical vapor are two methods to deposit different materials onto the semiconductor wafer.
The silicon wafer on the top surface is transformed into silicon dioxide.
The faults in the lattice can be repaired through diffusion.
Once all the processes in the IC fabrication process flowchart are completed, the IC is ready for packaging and post-fabrication testing and analysis. Cadence software offers tools to handle the entire IC fabrication process flow – from the integrated circuit design to packaging. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.