Abstract: An assembly flow in which integrated circuits are burned-in and parametrically tested before assembly is provided. The integrated circuits are sorted based on the results of the parametric testing, and assembled in groups with similar parameters. Integrated circuits from a single group are assembled on a leadframe and encapsulated, marked, and tested again while still attached to the leadframe. Finally, the packaged integrated circuits are separated from the leadframe and those meeting predetermined parameters are loaded into carrier sleeves.

Abstract: A method of actinic aligning semiconductor wafers which are coated with a contrast enhancement material is provided, wherein an alignment target formed on a semiconductor substrate which is coated with photoresist and contrast enhancement material is exposed to actinic wavelength light, while protecting active device areas from exposure. The contrast enhancement material over the alignment target is thus bleached so that the underlying alignment target becomes visible to actinic wavelength light. A pattern comprising an alignment pattern and an active device pattern is projected onto the wafer. The now visible alignment target is aligned to the projected alignment pattern with sub-exposure energy actinic light using conventional techniques and an actinic alignment tool, and the active device pattern subsequently exposed at an exposure energy of the actinic wavelength once the alignment is completed.

Abstract: An apparatus for use in high speed digital testing of high pin count logic circuits is provided wherein a plurality of terminal electronics units are connected in series to each other and to one channel of a multi-channel tester. Each pin electronics unit stores a test vector from the test channel in a first mode, and applies the test vector to the circuit under test at high speed in a second mode. Each pin electronics unit can also store response data from the circuit under test.

Abstract: A vertical field effect transistor having a first low resistivity region which determines breakdown voltage and a second low resistively region which is formed underneath a portion of a source is provided. The second low resistivity region lowers the gain of a parasitic bipolar transistor, and lowers resistance of a base region under the source of the field effect transistor, improving the commutating safe operating area of the vertical field effect transistor.

Abstract: A method of burning in integrated circuits on a semiconductor wafer is provided, wherein a burn-in chamber having a flexible membrane probe which is sized so that it can couple to a plurality of contact pads on the semiconductor wafer at one time. The semiconductor wafer is heated to a predetermined burn-in temperature and a bladder which lies behind the membrane probe is inflated so that the membrane probe couples to each of the plurality of contact pads on the wafer. The membrane probe is coupled to an exercise circuit which exercises all of the integrated circuits on the wafer in parallel for a predetermined time.

Abstract: An improved method for making a self-aligned vertical field effect transistor is provided wherein a nitride sidewall spacer is formed around a polysilicon gate, and an oxide sidewall spacer, which may be heavily doped with an n-type dopant, is formed covering the silicon nitride sidewall spacer. The silicon nitride sidewall spacer allows the oxide sidewall spacer of a conventional self-aligned vertical field effect transistor process to be removed partially or completely before making ohmic contact to the source thus increasing the contact area between the source and the source electrode and eliminating reliability problems related to n-type doped oxide in contact with aluminum electrodes.

Abstract: A structure and method for forming an isolation wall in an etched trench are described. The trench walls are covered by a thin silicon oxide layer and the trench conformally filled with an oxy-nitride mixture having a particular range of composition so as to produce a neutral to slight tensile stress in the oxy-nitride relative to silicon. The structure is very simple to fabricate and creates fewer defects in the silicon substrate than prior art techniques. Buried voids in the filled trench are eliminated.

Abstract: A heterojunction bipolar transistor (HBT) is provided having a silicon substrate in which a conventional junction base is formed. A coherently strained layer of semiconductor material having a wider band gap than silicon, such as gallium phosphide, is formed over the base to form a first portion of an emitter multilayer. A second portion of the emitter multilayer comprises silicon which can be epitaxially grown on the coherently strained layer. A thin heteropotential barrier is thus formed at the base-emitter junction which preferentially allows electrons to move from emitter to base while significantly reducing hole current from base to emitter, thereby improving emitter injection efficiency and current gain.

Abstract: A method for forming a via contact for devices having multilayer metallization is provided wherein a sacrificial layer is formed over a bottom interconnect layer, and an interlayer dielectric is formed on the sacrificial layer. A via is etched in the interlayer dielectric, exposing the sacrificial layer. The sacrificial layer is isotropically etched to expose an area of the interconnect metal that is larger than the area of the via and a via metallization is selectively formed on the interconnect metal by chemical vapor deposition so that the via, including a void created by the isotropic etch of the sacrificial layer, is filled with the via metallization, thereby providing a contact area to the bottom interconnect metal which is larger than the via metallization itself.

Abstract: A digital time base generator circuit is provided having a first phase locked loop for multiplying a reference frequency by an integer amount and a second phase locked loop for multiplying the reference frequency by a different integer amount. The first and second multiplied reference frequencies are then divided back down to the original reference frequency by two dual modulus frequency dividers. In this manner a start signal and a stop signal are generated such that the frequency of the start and stop reference signals is the same as the original reference frequency and the time delay between an edge of the start signal and edge of the stop signal can be changed by altering the mode of either of the dual modulus frequency dividers.

Abstract: A programmable pad printer which responds to an input signal by selecting one of a plurality of marks for transfer to a semiconductor. The input signal is provided to the printer from an external source, such as a semiconductor tester. The appropriate mark is then presented to an opening in a housing by rotating a disc containing the plurality of marks. A print head picks up the mark from the disc and transfers it to the semiconductor.

Abstract: An improved means and method for forming an optical sensor within an integrated circuit structure is described. An epi-coated semiconductor wafer is masked and a cavity etched through the epi-layer to the underlying substrate. A dielectric sidewall is formed on the cavity sidewall and a substantially intrinsic semiconductor region, preferably grown by selective epitaxy, to refill the cavity. The upper surface of the intrinsic region is then heavily doped and contacted by a low resistance polysilicon layer which is substantially transparent to incoming light. The method forms a high sensitivity PIN photo-sensor having a thick space-charge region for efficient capture of the hole-electron pairs produced by the incoming light. The fabrication techniques are compatible with the processing requirements for other integrated circuit devices formed on the same chip and to which the PIN device is coupled without wire bonds, tabs, bumps or the like.