Written submission from Pentagram Research UK Ltd (SEM0042)

 

Introduction

  1. The pentagram Research, headquartered in the UK has a roadmap of 20+ research projects from across the globe under different TRL levels. All of the projects undertaken will take commercial route for making UK to proud to hub of the innovation. The purpose of submitting the evidence is to address Q5 and Q6.
  2. We already have conducted significant preliminary work close to TRL level 3 and 4 by working on alternative to current semiconductor technology via molecular processing. Necessary governmental support will help out many UK corporate companies to lead ahead in semiconductor industry. Considering complexity of technology; Our company has explored the strong technical team from UK,  USA, Europe and India as a collaborative effort to take the current work to ultimate commercial success.

Disruptive Innovation in the field of semiconductor

  1. Government can strengthen semiconductor research and innovation by encouraging fundamental research engaged in disruptive technology using Molecular Electronic Devices. Molecular-scale electronic logic structures would occupy an area one million times smaller than analogous logic structures that currently are implemented in micron-scale solid state semiconductor integrated circuits.
  2. Molecular electronic devices exhibit immense parallelism. Government should support corporate to explore not only in the current semiconductor area for its limitation but possible alternatives that could become revolutionary in the times ahead in the area of Molecular devices.
  3. More frequent communication with stakeholders will bring in more serious work not only in the field of semiconductors but also explore any scope for alternatives. This will keep UK ahead in the field of innovation in such a critical industry acting as backbone supply chain provider to many industries like automobile, telecommunication and many others.

Introduction to Semiconductor alternative

  1. A computer system is made up of computing devices typically electronic logic gates and circuits. These devices facilitate the various computing operation inside a computer. In this regard our research work carried out is based on the design and operational aspects of molecular computing devices. These computing devices are electronic devices made from organic molecules or biomolecules.
  2. Our research is concerned with the problem of devising various means and methodologies as to design molecular devices in order to develop a molecular computer. The objective is whether it is possible to develop a single big molecular (or structural) formula which would act as a super computer.
  3. In order to achieve our objectives, efforts is in progress to design basic molecular building blocks, especially logic gates. It has further extended to design molecular combinational circuits and their derivatives. The molecular sequential circuits have been designed to make them suitable as computing devices for molecular computer.
  4. A research has been done on DNA based computing devices. At last a comparative study between silicon based computing devices, organic based computing devices and DNA based computing devices has done with respect to various performance factors responsible for designing a computer.
  5. Current computers are made of silicon and consist of atoms, but future computers may use molecules or clusters of atoms. This means the new field named as molecular electronics may overcome the complexity or have better computation in terms of designing the logical unit or processor as molecular electronic devices.
  6. Many scientific and technological innovations lead the semiconductor based electronic devices remarkable changes with miniaturization. But the rapid changes in miniaturization may lead to the microelectronic circuit components to reach the scale of atoms or molecules which is nothing but require conceptually new device structures in terms of molecules.
  7. Molecular-scale electronic logic structures would occupy an area one million times smaller than analogous logic structures that currently are implemented in micron-scale solid state semiconductor integrated circuits. It will be Technological Revolution. Industry predicts that silicon transistors can shrink to about 120 nanometers in length, but they are still more than 60,000 times larger in area available, if we consider molecular electronic devices. We can say the size factor leads a molecular computer would consume very little power and vast computing power. Not only with size, the material contents with a molecule carrying at a time with different chemical combinations which in other hand have different chemical properties giving rise to more speed to our molecular processor design. The accuracy will increase as we are finding different material combination with different energy level and with different chemical structures. The computing power or speed will be within nanosecond with latest design of robust computing algorithm taking in to consider the high throughput concepts.
  8. Theoretical Conceptualization of single molecule rectifiers proposed by Aviram and Ratner in 1974 was the beginning point of the new field of molecular electronics. In the meantime, experimental verification to molecular junctions has been reported. In this contribution, they worked with one of the molecular rectifiers system by studying the donor and acceptor parts of the molecules in terms of charge-transfer components.
  9. Our research work emphasizes the substituted molecule that gives different structures to donor-insulator - acceptor combination and the molecular orbitals formed by donor part and acceptor part. The molecular properties have studied purely taking organic molecules of choice and verifying the structure and bond properties that affects to the whole molecule.

Current Challenges and problems

  1. The evolution of computers and their architecture could be seen to be the result of a continuous research and development of electronic devices and the materials that have been used to fabricate such devices. These devices have been developed and constantly upgraded at par with advancement in silicon based design, optimization of physical layout and power consumption of silicon chips.
  2. The parameters which have a direct bearing in the design and fabrication of silicon based electronic devices are the following:
  1. The present day electronic chip manufacturers design and fabricate their devices only with the idea of reducing the size of the chips and of increasing their operational speed. Several methods have been devised and implemented so far to optimize chip size, speed and functioning of the integrated electronic devices. The limitation of downscaling conventional devices is mainly due to fabrication complexity, operational reliability, production capability, interconnects and economics of production. The limiting factors that affect downscaling of chip size are superposition, interference, entanglement, non-clonability, and uncertainty. So, one is always in a constant search for alternative technologies to design and develop ever wanted downscaled silicon chips. Nanotechnology and Micro Electro Mechanical Systems (MEMS) are the recent nonconventional technologies that have led to the design and fabrication of proto type nano electronic device structures which had apparently satisfied to certain extent the requirement of overcoming the limitations as stated above.

Moore’s Law Reinterpreted

  1. The silicon chip manufacturing industries have been constantly upgrading the operating standards of their foundries in order to overcome the limitations in the fabrication of downscaled silicon chips which operate with augmented speeds and with low power consumption. Front-end chip design with necessary software packages have indeed extended considerable support to chip manufacturers who have introduced automation in their foundries in the form of back-end machine codes for making masks and for fabricating silicon chips with required device specifications. Irrespective of the fact that one can make chip designs to any downscaled size using such software tools, the reality, on the other hand, is that the complexity of actually packing more and more devices in small size floor plans increases monotonically.
  2. According to Moore's Law, the number of transistors that could be embedded in a chip could be doubled once in 18 to 24 months. This means that the size of the transistors could be made smaller and smaller so that the operational speed of the chips could be faster and faster. However, as per the industry experts, the trend set by Moore's Law has already started working causing a slowdown in the realizably of further miniaturization of IC chips.

Performance of a Chip Based System

  1. The performance of computing devices depends on Size, Clock rate, System design and integration, Material used, Multiprocessing and Parallel processing. But, the limitation in the number of semiconductor devices to be embedded in a chip has set a limit to miniaturization to achieve greater performance. Much of a research has gone in to use novel structures and materials to extend the conventional technology for miniaturization but all in vain. Mr. Randy Isaac, Vice President for systems, technology and science research at IBM's Thomas J. Watson Research Center states "Even if they can be made smaller, at some point, smaller transistors may not perform faster; in fact, their performance could even be worse, if they worked at all."
  2. The chip performance depends mostly on the clock speed which in turn is related to the type of devices (transistors) that are used and on their switching characteristics. However, one can improve the overall performance of a chip based system by properly designing the architecture of the system with optimal layouts and even with lower clock speeds. Present day computers have their logic functions and memory devices on separate chips, which are situated in different boards. Data communication and control across such fragmented distances put forth further delays as processes wait for data and control signals to arrive. To overcome this difficulty, efforts are being made to incorporate various functions in to the same chip like microprocessor. Yet another way to improve system performance is by introducing parallel processing capabilities in the system. While multiprocessing ensures better performance, the high- speed processors used in a parallel processing system are generally power-hungry and they generate heat, a problem that calls for optimal layout considerations in the design stage itself. While today's microprocessors may burn only about 20 watts, tomorrow's faster processors may burn 100 watts and above. The only solution to overcome this problem is to use low-speed devices, which means poor performance of the system. Some of the questions that come under industry speculation are, (i) whether the improvement of the computer performance possible without faster transistors, (ii) will entirely new technologies supplement and extend the silicon transistors? and (iii) whether one needs a totally different kind of structures and materials that will replace the conventional technology?
  3. Present-day logic and memory chips are based primarily on CMOS (complementary metal-oxide semiconductor) transistor technology, so-called scaling laws - reducing the dimensions and voltage levels of an existing CMOS transistor in a coordinated way to produce a smaller, faster one. But literature survey shows that designers started to design silicon based devices using a 1.5 nanometer insulator as early as 2001, whereas the products are not available as on date.
  4. It was quoted that the operation of a transistor would be faster only when the length of the connections are shorter which means the time taken by a transistor to switch between cut-off and saturation levels is smaller. But in actual practice, the channel lengths cannot be shorter than 25 nanometers, a size that could be attained at a later date only with a sophisticated foundry technology.

Solution

  1. Thus the limitations described so far have led to a conclusion that future silicon based devices will not be made smaller and faster according to the time-tested scaling laws, though some modifications in the choice of the materials and in the design of optimal structure may keep the ball rolling for some years. Engineers and scientists including our organisation are now trying to find alternatives to silicon-based devices such as nanoscale devices which might be used for developing hardware meant for both traditional computing and nontraditional computing like symbolic computing.
  2. Any system, be it silicon based microcomputer or nanodevice based computer, would make use of sequential and combinational logic devices for carrying out basic arithmetic, logical and control operations. Any digital circuit could be designed using these devices. For example, digital circuits such as adders, timers, counters, registers, multiplexers are realized using the logical gates and flip flops. Logic gates and flip flops are designed and developed using bulk semiconductors. A digital IC is made up of billions of silicon atoms, where as a molecular logical gate may turn out to be a molecular formula consisting of a dozen molecules, may be some organic ones or biological ones like DNAs. The exciting point, of course, a matter of concern to be noted here is as to how to build such molecule based devices and interconnect them.

Beyond Silicon: Molecular Electronic Devices

  1. Nanotechnology is the science that deals with the study and fabrication of electronic devices in nano size level. This study has been carried out in two ways (i) the top- down approach where the electronic devices in a chip are scaled down to nano level and (ii) the bottom up approach where nano materials are chosen first and large systems are fabricated next. Let us assume that a typical conventional transistor is blown up to the size of an A4 size paper, then a molecular electronic device would occupy the space that contains just one line of characters. Even after decades, when industry predictions suggest that silicon transistors will have shrunk to about 120 nanometers in length, they will still be more than 60,000 times larger in area than that of molecular electronic devices. The purpose of nanotechnology research is to device various methodologies of using individual atoms and molecules to work as electronic devices which are thousands of times smaller than the size of similar semiconductor devices that the current technologies permit as on date. Current manufacturing processes use lithography to imprint circuits on semiconductor materials. While lithography has improved dramatically over the last two decades -- to the point where some manufacturing plants can produce circuits smaller than one micron (1,000 nanometers) -- it still deals with aggregates of millions of atoms. It is widely believed that lithography is quickly approaching its physical limits. To continue reducing the size of semiconductors, new technologies that juggle individual atoms will be necessary. This is the actual realm of nanotechnology. Moreover, the size advantage means a molecular computer may consume very little power and has vast computing power. No doubt, this field of study is in the initial stages of research and development and would take more time to reach the stage of actual development and productization.
  2. Not only the size that matters for achieving high speed computing with less power consumption, the choice of the molecules, their molecular structures and their chemical properties would also play significant roles in achieving high performance computing. The robustness and accuracy will increase when different combinations of molecules with different energy levels and with different chemical structures are considered. The computing power or speed could be further increased with the formulation and effective use of high throughput symbolic computing algorithms instead of traditional numerical algorithms.

Molecular Computing – The Need of the hour

  1. The two major reasons to go in for molecular computing are (i) molecular-scale electronic logic structures would occupy an area one million times smaller than analogous logic structures that currently are implemented in micron-scale solid-state semiconductor integrated circuits and (ii) molecular electronics devices exhibit immense parallelism.
  2. Molecular electronic devices (both organic and biological) have the following advantage when compared to semiconductor devices:
  1. We also need to consider challenges in assembling, stability (as molecules are highly unstable), time variance (time variance property is not fully satisfied) , casualty (for any output there must be same input) in designing the electronic device or molecular electronic systems. Molecular electronics is an interdisciplinary subject that encompasses physics, chemistry and materials science and it mainly advocates the use of molecular building blocks for the fabrication of various devices. Molecular electronics provides a means to extend Moore's Law beyond the foreseen limits of small-scale conventional silicon integrated circuits. Due to the broad use of the molecular electronics, it is split into two related but separate sub disciplines (i) molecular materials and (ii) molecular electronics.
  2. The field of molecular materials deals with analysis of physical and chemical properties of various organic and biological molecules and identification of those molecules which are suitable for fabricating devices, whereas, the field of molecular electronics deals with the actual development of devices using such molecules.
  3. A molecular machine is defined as a network of discrete number of molecular components, that is, devices designed to yield specific outputs in response to specific inputs. The term is also common in nanotechnology and a number of highly complex molecular machines have been proposed towards the goal of constructing a molecular assembler. In order to construct a molecular machine or system, we need to have a deep understanding of how molecules can actually compute.

Objective and Scope

  1. To be very precise, the objective of this research is to design various building blocks consisting of structured molecules which could be subsequently used for building molecular electronic circuits.
  2. The sub objects that are incidental to main objectives are
  1. In order to achieve these objectives, efforts have been made to understand existing technologies and modify or rectify them in order to suit to the requirements of the objectives.
  2. In the first phase, a systematic work of various technical matters available in the literature as on date was made. In the second phase, efforts have been made to identify loopholes and lacunae in the existing techniques which could possibly be rectified or modified. In the third phase, efforts have been made to develop means and methodologies for designing basic building blocks, especially logic gates. In the fourth phase, efforts have been made to make use of these building blocks for developing sequential circuits and combinational circuits and their derivatives.
  3. In the sub system level, the structural formulae of these circuits have been optimized by bonding various aliphatic substances in order to improve the current density and overall performance so that each electronic circuit could be viewed as a well-structured chemical formula. In the last phase, efforts have been made to identify a universal formula for a molecular super computer which will consist of terabytes of memory, millions of counters and registers and other essential sub systems.

Current status

  1. Theoretical work has been carried out so far. The state-of-the-art technique to design any type of digital device using molecules has been developed as on date, which has to be validated in a formal framework.

Making UK the leader

  1. The above solution and research work by us in Molecular devices and fabricate to call it as Molecular Processors. This will make UK leader in semiconductor space given the current scenario the world is facing. UK could become potential solution provider to the world by providing Molecular devices as replacement to semiconductor based devices. Our organization based in UK has already made humble beginning of collating the data and team of scientists from across the UK, USA, Europe and young talents from India. UK is well positioned respond by attracting required skills, talent and diversity to disrupt current semiconductor industry.

 

From the desk of Scientific team,

Pentagram Research UK Ltd.

 

www.pentagramresearch.co.uk

 

contact@pentagramresearch.co.uk