VLSI is the worst thing ever happened to me, joked one of my batchmate after taking EE5323 at the semester end. I got a mini-heart attack cause it was best thing ever for me (and she was a girl... there vlsi lost another girl for it's aspirants). So, hope this document inspires or warns future student.
Aim: to understand scope of VLSI and the courses offered at UMN
To be used: On a bright, lazy morning cause the doc will be lengthier (have center fresh chewing gum, if you find VLSI boring :P) Skip to the last part of course, if you are too bored :)
So, let's understand the prospect of VLSI with a VLSI centric world and how the courses here cater to those demands (VLSI says sorry to other EE dept ppl for it's selfishness here :P)
There are two types of jobs: VLSI design and supporting jobs. So here is a typical chip life cycle
There are product architects from different VLSI application field (DSP, communication, wireless, etc). They define the product (IC) at the top level. They need to have a basic understanding of system, computer architecture, not much on circuits or devices though. Once the architecture is finalized, the chip description is being coded at the top level through HDLs (Hardware Description Langauge like Verilog, System Verilog, VHDL) this is called coding and RTL design. These are done at logic level or gate level. So, these engineers need to know basic digital logic design, systems and circuits apart from HDLs; not much devices (electrical aspects) though. Since this phase take long time, a parallel team of programmers write the system model in language called System C and test those modules. These testing can be done in different language for the functionality that the architects intend to get out of the chip. This is testing and the engineer needs to know same thing as RTL design engineers. The end product here is a transistor level code of IC called netlist. The phase from architecture to netlist is called front-end. This phase also contains phases like DFT (design-for-test), STA (Static Timing Analysis), RTL testing, etc.
The netlist code is handed over to back-end or physical designer. Picture this, a software is the final phase of realization, but for hardware code to be realizable - it needs to be manufactured on a physical media (Silicon wafer mainly). The netlist is taken and realized in terms of transistor schematics. This is called circuit design. They check electrical aspects (ac and dc analysis - timing, power, noise). Then this is drawn on a virtual silicon wafer through software tools. This is called layout. The final product is a GDSII, which contains the layout information. These engineers needs to know circuits, logic design, HDLs (they deal with it when taking it from front-end), system, device and fabrication. These are the main guys, who extensively deal with every kind of electrical aspects of chip. (With so much appreciation towards this field, you must have known i am a physical designer)
Both the front-end and back-end is supported by huge computing resources (EDA domain - Electronic Design Automation). These are the VLSI automation tools that support these design engineers to work better and faster in the most advanced technology. They need to know more computers than electrical aspect. Algorithm, C/C++ language, digital logics, computer architecture, system/circuit concepts are some of the desired quality. They also need to support their tool. These are one of the top paid guys in the industry, but work profile is not as satisfactory as designing (my opinion and experience - they can be disturbed at night 2am also and poor guys can't complain too)
The GDSII is sent to fabrication units to be fabricated into chips. The fabrication people need to know devices and VLSI technology (fabrication, semiconductor physics, mechanical engineering, etc). There are other sets of engineers, who decide about chip packaging, wiring and maintenance. These guys need to know materials and electrical aspects (mostly power). According to system type, there are engineers like digital engineer (most of the cicuits are digital), analog engineer (can't exist without digital and vice versa), RF/wireless (mostly part of analog), optics (you know it), power electronics (high voltage devices, i guess- correct me here), etc. And of course how can we forget the researchers - Nano/Micro electronics/technology guys. These are the guys, who find new devices and technology to keep advancing the technology day by day. The advanced domain is more of a research topic with very few commercial usage, because most of technology innovation is done by fab people. Although in recent years, discovery of nanotubes and new means of representing digital logics have infuses funds into the research. These guys needs to know solid state, materials, semiconductor physics, quantum physics, microfab, etc.
So, here is a summary of the scopes:
Architects - develop chip architecture
Front-end engineer - design, develops and test HDL implementation of chip
Back-end engineer - design, develops and verifies transistor and layout implementation of IC
Automation engineer - develop and support flows and tools for designers
Fabrication engineer - manufacture and tests physical IC
Digital engineer - Most public at UMN, friendly, smart and handsome
Analog engineer - conspire with Professor Harjani and make life of digital aspirants hell
RF/Wireless - Analog students who have no other courses left to take
optics - most american, Iranian and international students in those courses at UMN
power electronics - heavily funded and super-rich guys in UMN
Nano-electronics - The gen-next (same public as optics)
Oh shit... it's too huge - let's publish it as a part 1 doc and have dinner... birthday party to attend at midnight too... Courses info coming next... Any discrepancy, please let me know and correct it here...
FAQ:
Q: .can u please comment on the role of analog/microelectronics engineers in the above design process u have explained ?..and also elaborate on how analog design students conspire with prof harjani :p?A: Microelectronics as it names suggest is electronics at the micron range - so VLSI dealing with electronics of micron range devices or ckts is called microelectronics (though most advanced nodes are at nano level now). Guys here learn devices, ckts and systems. Then they chose their domain - ckt design (mainly), Layout or fabrication, sometimes front-end, etc. Micro-electronics is a wide field and not a job description as such. Analog guys do analog design. Digital engineer's main priority is advanced node, power, speed, cost; while analog designers have different priority. Due to the sensitivity of their design (remember they don't deal with just 5V and 0V like digital designer - they need a proper 3V if they want a 3V, which for digital designer is a 5V), their priority is mainly to do proper circuit design and layout for a definitive behavior after fabrication. So, they don't deal with advanced technology rather a matured technology (proven old one). Their challenge is bandwidth, noise, functionality, gain, slew rate, etc. Some analog design include A/D or D/A converter, Op-amps, Oscillators, OTA (project of EE5333), filters, etc.
