Static induction transistor

About: Static induction transistor is a research topic. Over the lifetime, 8155 publications have been published within this topic receiving 107058 citations. The topic is also known as: SIT.

Nonvolatile semiconductor memory device employing transistors having different gate withstand voltages for enhanced reading speed

Abstract: A semiconductor device includes a plurality of nonvolatile memory cells (1). Each of the nonvolatile memory cells comprises a MOS type first transistor section (3) used for information storage, and a MOS type second transistor section (4) which selects the first transistor section. The second transistor section has a bit line electrode (16) connected to a bit line, and a control gate electrode (18) connected to a control gate control line. The first transistor section has a source line electrode (10) connected to a source line, a memory gate electrode (14) connected to a memory gate control line, and a charge storage region (11) disposed directly below the memory gate electrode. A gate withstand voltage of the second transistor section is lower than that of the first transistor section. Assuming that the thickness of a gate insulating film of the second transistor section is defined as tc and the thickness of a gate insulating film of the first transistor section is defined as tm, they have a relationship of tc

Load current supply circuit having current sensing function

Abstract: A load current supply circuit having a current sensing function is composed of a current mirror circuit which includes a power transistor circuit and a sense transistor circuit both connected in parallel with each other, and a current detection circuit connected to the sense transistor circuit. Load current is drawn through the power transistor while sensing current which is proportional to the load current and is much less than the load current flows through the sense transistor. The current detection circuit detects the load current based on the sensing current. A current mirror ratio has to be constant under a wide range of ambient temperature in order to secure a current sensing accuracy. To maintain the current mirror ratio at a substantially constant level, a resistance ratio of wiring resistance to transistor ON-resistance in the sense transistor circuit is made substantially equal to that in the power transistor circuit. For this purpose, compensating resistors may be disposed at both sides of the sense transistor in the sense transistor circuit.

Variable gate bias for a reference transistor in a non-volatile memory

Abstract: A non-volatile memory (30) comprises nanocrystal memory cells (50, 51, 53). The program and erase threshold voltage of the memory cell transistors (50, 51, 53) increase as a function of the number of program/erase operations. During a read operation, a reference transistor (46) provides a reference current for comparing with a cell current. The reference transistor (46) is made from a process similar to that used to make the memory cell transistors (50, 51, 53), except that the reference transistor (46) does not include nanocrystals. By using a similar process to make both the reference transistor (46) and the memory cell transistors (50, 51, 53), a threshold voltage of the reference transistor (46) will track the threshold voltage shift of the memory cell transistor (50, 51, 53). A read control circuit (42) is provided to bias the gate of the reference transistor (46). The read control circuit (42) senses a drain current of the reference transistor (46) and adjusts the gate bias voltage to maintain the reference current at a substantially constant value relative to the cell current.

Insulated gate silicon carbide semiconductor device

Abstract: An insulated gate silicon carbide semiconductor device is provided having small on-resistance. The device combines a static induction transistor structure with an insulated gate field effect transistor structure. The advantages of both the SIT structure and the insulated gate field effect transistor structure are obtained. The structures are formed on the same SiC semiconductor substrate, with the MOSFET structure above the SIT structure. The SIT structure includes a p + gate region in an n-type drift layer on an n + SiC semiconductor substrate, and an n + first source region on the surface of the drift layer. The MOSFET structure includes a p-well region on the surface of the first source region, a second source region formed in the p-well region, and a MOS gate structure formed in a trench extending from the second source region to the first source region. The p + gate region and a source electrode are conductively connected.

Dynamic threshold voltage MOSFET on SOI

Abstract: Provision of a body control contact adjacent a transistor and between the transistor and a contact to the substrate or well in which the transistor is formed allows connection and disconnection of the substrate of the transistor to and from a zero (ground) or substantially arbitrary low voltage in accordance with control signals applied to the gate of the transistor to cause the transistor to exhibit a variable threshold which maintains good performance at low supply voltages and reduces power consumption/dissipation which is particularly advantageous in portable electronic devices. Floating body effects (when the transistor substrate in disconnected from a voltage source in the “on” state) are avoided since the substrate is discharged when the transistor is switched to the “off” state. The transistor configuration can be employed with both n-type and p-type transistors which may be in complementary pairs.