摘要:
A test methodology which provides that test structures, such as transistors, are arranged in a plurality of rows. A logic circuit controls which row is to be measured. An incrementer receives a triggering signal and functions as an address adder. Each time the triggering signal rises from 0 to 1, the output of the incrementer increases by 1. The output of the incrementer serves as the address input into a decoder. The decoder is connected to the rows of test structures. Preferably, each test structure contains a control circuit which is controlled by this signal (i.e., the output of the decoder). If the test structures are transistors, bias to each of the transistors can be applied separately with a common gate, source and well, and measurement can be done with a separate drain node.
摘要:
A test methodology which provides that test structures, such as transistors, are arranged in a plurality of rows. A logic circuit controls which row is to be measured. An incrementer receives a triggering signal and functions as an address adder. Each time the triggering signal rises from 0 to 1, the output of the incrementer increases by 1. The output of the incrementer serves as the address input into a decoder. The decoder is connected to the rows of test structures. Preferably, each test structure contains a control circuit which is controlled by this signal (i.e., the output of the decoder). If the test structures are transistors, bias to each of the transistors can be applied separately with a common gate, source and well, and measurement can be done with a separate drain node.
摘要:
Test structures are provided for accurately quantifying shared contact resistance. The test structures are built based upon an actual memory cell, which is self-aligning to allow shared contact chains through an array of test cells. A main array of test cells is built to provide a chain of shared contact resistance. Using the main array of test cells, a resistance in the shared contact chain may be measured. Supplemental arrays of test cells is built to provide a chain of poly side resistance, a chain of island side resistance, a chain of island connection line resistance, and a chain of poly connection resistance. A tester measures resistance using the test structures and uses the values to accurately determine shared contact resistance.
摘要:
The present invention is test structures in unused areas of semiconductor integrated circuits and methods for designing the same. In an exemplary aspect of the present invention, a method for placing test structures in a semiconductor integrated circuit includes: (a) detecting a dummy area in a semiconductor integrated circuit, the semiconductor integrated circuit including probe pads on a top metal layer; (b) filling the dummy area with active test cells, the active test cells being connected to one another; and (c) connecting each of the active test cells to the probe pads with a metal line.
摘要:
Test structures are provided for accurately quantifying shared contact resistance. The test structures are built based upon an actual memory cell, which is self-aligning to allow shared contact chains through an array of test cells. A main array of test cells is built to provide a chain of shared contact resistance. Using the main array of test cells, a resistance in the shared contact chain may be measured. Supplemental arrays of test cells is built to provide a chain of poly side resistance, a chain of island side resistance, a chain of island connection line resistance, and a chain of poly connection resistance. A tester measures resistance using the test structures and uses the values to accurately determine shared contact resistance.
摘要:
The present invention is test structures in unused areas of semiconductor integrated circuits and methods for designing the same. In an exemplary aspect of the present invention, a method for placing test structures in a semiconductor integrated circuit includes: (a) detecting a dummy area in a semiconductor integrated circuit, the semiconductor integrated circuit including probe pads on a top metal layer; (b) filling the dummy area with active test cells, the active test cells being connected to one another; and (c) connecting each of the active test cells to the probe pads with a metal line.
摘要:
An integrated circuit structures such as an SRAM construction wherein the soft error rate is reduced comprises an integrated circuit structure formed in a semiconductor substrate, wherein at least one N channel transistor is built in a P well adjacent to one or more deep N wells connected to the high voltage supply and the deep N wells extend from the surface of the substrate down into the substrate to a depth at least equal to that depth at which alpha particle-generated electron-hole pairs can effectively cause a soft error in the SRAM cell. For a 0.25 &mgr;m SRAM design having one or more N wells of a conventional depth not exceeding about 0.5 &mgr;m, the depth at which alpha particle-generated electron-hole pairs can effectively cause a soft error in the SRAM cell is from 1 to 3 &mgr;m. The deep N well of the 0.25 &mgr;m SRAM design, therefore, extends down from the substrate surface a distance of at least about 1 &mgr;m, and preferably at least about 2 &mgr;m. In a preferred embodiment, the implantation of the substrate to form the deep N well of the improved SRAM of the invention is carried out in a manner which will cause straggle, i.e., cause the doped volume comprising the deep N well to broaden at its base. Such a broadened base deep N well will have enhanced opportunity to collect electrons generated by the alpha particle collision with the substrate. This deep N well with a broadened base can be formed either by increasing the implant energy or by tilting the substrate with respect to the axis of the implant beam while implanting the substrate to form the deep N well.
摘要:
A method of forming a memory cell according to the present invention. A first pass gate transistor is formed of a first transistor type. The first pass gate transistor has a gate oxide with a first thickness. The source of the first pass gate transistor is electrically connected to a first bit line, and the drain of the first pass gate transistor is electrically connected to a first state node. The gate of the first pass gate transistor is electrically connected to a memory cell enable line. A second pass gate transistor is also formed of the first transistor type. The second pass gate transistor also has a gate oxide with the first thickness. The source of the second pass gate transistor is electrically connected to a second bit line, and the drain of the second pass gate transistor is electrically connected to a second state node. The gate of the second pass gate transistor is electrically connected to the memory cell enable line. A first state node transistor is also formed of the first transistor type. The first state node transistor has a gate oxide with a second thickness. The source of the first state node transistor is electrically connected to the first state node, and the drain of the first state node transistor is electrically connected to a ground line. The gate of the first state node is electrically connected to the second state node. A second state node transistor is also formed of the first transistor type. The second state node transistor also has a gate oxide with the second thickness. The source of the second state node transistor is electrically connected to the second state node, and the drain of the second state node transistor is electrically connected to the ground line. The gate of the second state node is electrically connected to the first state node.