International Business Machines Corporation

Synopsys, Inc.

Synetry Corporation

Donald A Soderman

Victor M Simi

Vincent L Rideout

Cheng-Yih Liu

Ronald P Esch

Denis R Coleman

Robert M Folsom

Yuri V Panchul

Claude Louis Bertin

Lawrence G Heller

Harish N Kotecha

Francisco H De La Moneda

Harry J Jones

George T Wenning

G Thomas Wenning

A computer aided hardware design system for enabling design of an actual hardware implementation for a digital circuit using a high-level algorithmic programming language. The system converts an algorithmic representation for a hardware design initially created in the high-level programming language, such as ANSI C, to a hardware design implementation, such as an FPGA or other programmable logic or an ASIC. The C-type program representative of the hardware design is compiled into a register transfer level (RTL) hardware description language (HDL) that can be synthesized into a gate-level hardware representation. The system additionally enables simulation of the HDL design to verify design functionality. Finally, various physical design tools can be utilized to produce an actual hardware implementation. The system also permits the use of other non-C-type high-level programming languages by first translating to a C-type program. In contrast to previous hardware design tools, the system compiles all C-type programming language features, including pointers and structures, into synthesizable HDL.

System for converting hardware designs in high-level programming languages to hardware implementations

System for converting hardware designs in high-level programming language to hardware implementations

The invention is the structure and process for making a bucket brigade device which comprises the merger of an MOS capacitor with an MOSFET device to form the charge transfer cell. A first thin N-type region is implanted at a first concentration in a portion of the P-type channel region of an FET device adjacent to the drain diffusion. A second region is implanted with N-type dopant at a second concentration less than the first concentration, adjacent to and continuous with the first implanted region. The N-type concentration in the second region is just sufficient to compensate for the P-type background doping in the channel region. This structure increases the charge transfer efficiency for the cell and reduces its sensitivity of the threshold voltage to the source-drain voltage. The gate for the device has a substantial overlap over the drain and a minimal overlap over the source and the gate to drain capacitance per unit area is maximized by maintaining a uniformly thin oxide layer across the gate region.

Process for making a dual implanted drain extension for bucket brigade

A diffused MOS (DMOS) device and method for making same are disclosed. The prior art DMOS device is improved upon by ion implanting a depletion extension L.sub.D to the drain. However, the introduction of the depletion extension L.sub.D introduces a manufacturing statistical variation in the characteristics of the resultant devices so produced. The problem of the effects of the variations in the length L.sub.D and thus, variations in the resulting transconductance of the device, is solved by placing two of these devices in parallel. When one device has its L.sub.D relatively shorter, the companion device will also have its L.sub.D correspondingly longer. The method of producing the dual devices is by ion implanting a single conductivity region which forms the L.sub.D for both the left- and right-hand channels for the left- and right-hand DMOS structures. If the mask for the ion-implanted region is misaligned slightly to the right, then the effective L.sub.D for the right-hand channel is somewhat longer but the effective L.sub.D for the left-hand channel is correspondingly shorter, so that the net parallel transconductance for the two devices remains the same as the transconductance for a perfectly symmetric ion-implanted region.

Method of making a dual DMOS device by ion implantation and diffusion

A dynamic random access memory is fabricated on a monolithic chip of semiconductor material. The memory is formed of an array of memory cells controlled for reading and writing by word and bit lines which are selectively connected to the cells. Each cell is a single field effect transistor structure having improved electrical charge storage capability. The improved charge storage capability of each cell is provided by an electrical capacitance structure uniquely arranged and formed as an integral portion of the field effect transistor structure. The gate electrode of each field effect transistor structure is connected to a predetermined one of said word lines. The drain of each field effect transistor is connected to a predetermined one of said bit lines. The source of each field effect transistor structure is integrally connected to and forms a portion of the uniquely arranged electrical capacitance structure of the field effect transistor structure. The electrical capacitance or storage node structure of each cell has increased electrical charge storage capacity and may be considered as a single capacitor. The single (storage) capacitor of each cell is provided between the source of the field effect transistor, a source of reference potential (reference plane) and the monolithic semiconductor substrate on which the memory is fabricated. The arrangement of the memory cells, the structure and material of each of the memory cells, and a method of fabricating the entire memory is disclosed. Also disclosed is an improved field effect transistor structure and process for fabricating same. The process of fabrication, cell arrangement and the improved storage node of each memory cell, as structurally fabricated and uniquely arranged, provides a monolithic memory having improved density and operating characteristics.

Method of fabricating random access memory device

One-device monolithic random access memory and method of fabricating same

The invention is the structure and process for making a bucket brigade device which comprises the merger of an MOS capacitor with an MOSFET device to form the charge transfer cell. A thin n-type region is implanted in a portion of the p-type channel region of an FET device adjacent to the drain diffusion. This structure increases the charge transfer efficiency for the cell and reduces its sensitivity of the threshold voltage to the source-drain voltage. The gate for the device has a substantial overlap over the drain and a minimal overlap over the source and the gate to drain capacitance per unit area is maximized by maintaining a uniformly thin oxide layer across the gate region.

Improved process to form bucket brigade device

Bucket brigade device and process

Growing community of inventors

Vienna, VA, United States of America

Donald A Soderman