VLSI: Development and basic principles of IC Fabrication

With the decreasing feature sizes and increasing chip areas, silicon microchips have been broadly doubling their component counts per chip every two years. This relentless exponential growth in the component counts has maintained its trend throughout the eighties also, leaving the VLSI design methods struggling to cope as the actual component counts possible on chips have reached the figure of one million towards the close of the decade. 

Research in VLSI digital circuits includes a microprocessor and mixed-signal (microcontroller) circuits, with emphasis on low-power and high-performance; computer-aided design, including logic synthesis, physical design, and design verification; testing and design for testability; advanced logic families and packaging; integrated circuit micro-architectures; and system integration.

A VLSI device is commonly known as the microcontroller. Before VLSI, most ICs had limited functions. An electronic circuit usually consists of a CPU, ROM, RAM and other peripherals on one board. VLSI lets IC designers add all of these into one chip. Let’s look into the backstory of VLSI development before going into specifics.

An integrated circuit through the years 

The first integrated circuits contained only a few transistors. Early digital circuits containing transistors in tens, provided a few logic gates and early ICs had as few as two transistors. The number of transistors in an IC has increased dramatically since then.

VLSI Advantages: 

The increase in density happens through multiple developments. Some of which would be a reduction in size, management in power consumption among others,

• Reduces the size of circuits
• Reduces the effective cost of the devices
• Increases the operating speed of circuits
• Requires less power than discrete components
• Higher reliability
• Occupies a relatively smaller area

Designing a VLSI IC 

The design of a VLSI IC consists broadly of 2 parts. Front end design includes digital design using HDLs such as Verilog, VHDL, SystemVerilog and the like. 

Today, VLSI design flow is a very solid and mature process. The overall VLSI design flow and the various steps within the VLSI design flow have proven to be both practical and robust in multi-millions VLSI designs until now.

Every step of the VLSI design flow has a dedicated EDA tool that covers all the aspects related to the specific task perfectly. And most importantly, all the EDA tools can import and export the different file types to help making a flexible VLSI design flow that uses multiple tools from different vendors.

These tools can actually be of help to the consumer industry; wherin the overal production cost is cut to zero.