Hochschule Kempten      
Fakultät Elektrotechnik      
Microelectronics       Fachgebiet Elektronik, Prof. Vollrath      

Microelectronics

02 History

Prof. Dr. Jörg Vollrath


01 Introduction


Video of lecture 03 24.03.2021


Länge: 1:02:33 min
0:0:54 Transistor, Layout, Cross Section

0:4:5 Transistor count

0:9:5 Moore's Law: Feature Size

0:13:0 Microelectronics over time

0:16:20 iFixit iPhone Analysis

0:18:5 iPhone Main Board

0:19:40 Blessing and Curse of Microelectronics

0:22:48 Design Entry

0:27:5 Software Tools

0:28:35 Integrated Circuit Challenges

0:29:55 Laboratory: Build a 4 bit positive number multiplier

0:32:43 Hierarchical description, one solution

0:36:40 Citations: Don't optimize too early.

0:39:19 Design flow

0:43:25 Technologies

0:47:15 Inverter schematic

0:49:45 Truth table

0:51:13 Source drain, schematic, color, layout box

0:54:5 Stick diagram

0:56:13 What do I do with 1 billion transistors?

0:57:32 Inverter schematic and layout

1:2:5 p-well and n-well

1:5:57 p-well and n-well contact

1:8:31 Layout well contact

1:12:45 F and lambda

1:13:29 N-MOSFET equations

1:16:16 β, width W, length L, capacitance Cox

1:22:4 0

Review and Overview


Transistor Evolution

Nachbau des ersten Transistors
Quelle: Wikimedia 1947 Bell
1 Bipolar transistor
30 μ m

50 MHz

Courtesy of Intel
2008 Intel Core i7
731 Million MOS Transistors
45 nm process
263 mm2
2.6..3.2 GHz

It can be seen that the Intel Core i7 has 731 million transistors in a process using 45nm feature size on an area of 263 mm2. As an critical thinking engineer it is important to be able to check statements, claims and facts.
In this example the number of transistors for the given chip area is checked. A single transistor needs a minimum size of 16 F2 as seen before. The number of transistors is chip area (AChip) divided by transistor area (AMOSFET).
263 mm2/(16 * (45nm)2) = 8117 Mio Transistors.
This is a factor of 11 higher than the claimed 731 million transistors.
In highly integrated chips the total size is not limited by the area of transistors, but by the area needed for contacts and wiring.
In a microprocessor one transistor needs around 180 F2. This number is important for estimation of chip area for a given circuit with a given number of transistors.

Links:
http://www.intel.com/pressroom/archive/releases/2008/20081117comp_sm.htm
http://download.intel.com/pressroom/kits/corei7/images/Nehalem_Die_Shot_3.jpg
http://www.tomshardware.com/de/Core-i7-Nehalem,testberichte-240172-2.htm
https://en.wikipedia.org/wiki/List_of_Intel_Core_i7_microprocessors

History of integrating microelectronic circuits


Electronic components


http://en.wikipedia.org/wiki/File:RCA_%E2%80%99808%E2%80%99_Power_Vacuum_Tube.jpg
http://www.ti.com/corp/docs/company/history/tihistory_subpage1.shtml
http://www.icknowledge.com/history/1970s.html

Moore's Law: Transistor count 2020

Moore's Law Transistor Count 1970-2020
Every 2 years the number of transistors per area doubles.
Each year manufacturing productivity gains are about 30%.

Moore's Law: Feature size

Comparison semiconductor process nodes

Microelectronics over time

Benefits



Challenges



Mobile phone components

iPhone 3 GS Teardown
iPhone-3GS
Source: iFixit CC BY-NC-SA 3.0

Mobile phone components

A18 SoC, 8GB LPDDR5 SDRAM, Kyoxia 128GB NAND Flash-Speicher iPhone 16 Pro Teardown
iPhone 16 Pro, Source: iFixit
It is also very interesting to see the 3D integration since one PCB sits on top of the other.

Mobile phone main board

iPhone 3 GS Teardown
Source: iFixit CC BY-NC-SA 3.0
Samsung ARM processor S5PC100 600MHz

16 GB of Toshiba NAND flash memory
NOR Pseudo SRAM Numonyx
256MB DDR SDRAM

Analog Broadcom, Infineon

Power Management Infineon, NXP

Blessing and curse of microelectronics

Design and manufacturing
Blessings:
Curse (Challenge):

MOSFET Transistor


Quelle Vollrath
Quelle Vollrath
TechnologyRNRP COXVthn VDD IDDgmmax gdmaxft Model
1 μm15kΩL/W45kΩL/W 1.75fF WL/F21V 5V 3 mA cmosedu_models N_1um
600 nm ΩL/WΩL/W fF WL/F2 V mA C5_models
50 nm 34kΩ/W68kΩ/W 62.5aF WL/F20.3 V 1 V mA cmosedu_models N_50nm

MOSFET


A MOSFET (Metal oxide semiconductor field effect transistor) has the terminals gate (G), source(S), drain(D) and bulk(B). The gate controls current flowing between source and drain. There is a threshold voltage Vth which is needed to enable current flow. A bulk potential and bulk connection can change threshold voltage. Therefore bulk connections are needed to guarantee a stable threshold voltage.
There are enhancement mode PFETs and NFETS available making CMOS (complementary MOS) circuits possible. Enhancement mode FETS have a threshold voltage so that no current is flowing with 0V between source and gate.
NFETs have a positive threshold voltage, PFETS have a negative threshold voltage.

Transistor representation


Transistors as electrical components can be small black boxes with 3..4 wires. They are represented in a schematic as a symbol. In microelectronics a transistor is represented by a red rectangle (polysilicon) crossing a green rectangle (diffusion). Connections betweeen different colored areas are represented by black boxes between overlapping colored rectangles. Metal lines for connections are drawn as blue, violet or pink boxes.
In microelectronics circuits are built by transfering a transistor schematic to a layout (colored shapes). There are design rules limiting the size and distance of these colored boxes due to the limitations of the manufacturing process.

Minimum feature size and transistor area


The minimum total area of a transistor is based on the minimum feature size F.
The minimum feature size is the smallest pattern which can be realized in a given manufacturing process. The minimum feature size is depending on the wavelength of the used light source for the photoprocess used to transfer patterns with a mask onto the photoresist on a chip. A MOSFET uses at least 3 connections with minimum square area of F2. Since there should be no shorts a distance to the next feature should also has a minimum distance of 1 F. Therefore 3 connections and one active transistor area, where a red and green line are crossing, with isolation require:
4 * 4 F2 = 16 F2

Tools

Design Entry

Schematic


Layout


Graphical State machine


VHDL


SystemC


C/C++






Result: Integrated Circuit


Courtesy of Intel
http://www.intel.com/pressroom/archive/releases/2008/20081117comp_sm.htm
http://download.intel.com/pressroom/kits/corei7/images/Nehalem_Die_Shot_3.jpg

Integrated Circuit Challenges

2025 Serial CPU Investigation


  • A simple configurable cell for serial computing should be designed.
  • Input:
    CLK clock, CE, RST, TE, TDI, TDO
    2 or more serial data inputs A0, A1,.., An
    1 serial configuration pin (can an input be used for configuration
  • Output: 1 or more serial data outputs Y0, Y1, .., Yn
  • Operations
    • Delay: 1,2,3,4,..n/1,2,4,8,16,.. cycles
    • Add: A0 + A1, A0 + preset
    • Multiply/Shift: A0 * A1, A0 * preset
    • Integrate (Accumulate), Differentiate
    • Compare: A0,A1; A, fixed value
    • Multiplex A0 or A1 to A0..An
    • Fixed sequence output Y0..Yn
  • Functions
    • Receive and transmit serial/parallel data (SPI, I2C, UART, SERDES)
    • Static, repetitive output: All 0, All 1, serial 0,
    • Counter: Binary, Gray, thermometer (PWM)
    • Change length of serial stream
    • Multiplex
    • Sort A0, A1, An to Y0, Y1, ..., Yn

Next: LTSPICE and Electric


Circuit simulator: LTSPICE

Layout tool: Electric

03 MOSFET transistor

Lecture and Laboratory


2022 Compare Adder Architectures

Lecture and Laboratory


2021 Build a 4 bit postive number multiplier

Old Moore's Law (2011): Transistor count

Transistor Count and Moore's Law - 2011
Every 2 years the number of transistors per area doubles.
Each year manufacturing productivity gains are about 30%.