A through-wafer interconnect for imager, memory and other integrated circuit applications is disclosed, thereby eliminating the need for wire bonding, making devices incorporating such interconnects stackable and enabling wafer level packaging for imager devices. Further, a smaller and more reliable die package is achieved and circuit parasitics (e.g., L and R) are reduced due to the reduced signal path lengths.

Through-wafer interconnects for photoimager and memory wafers

Recent progress in GaN based high electron mobility transistors (HEMTs) has revealed them to be strong candidates for future high power devices with high frequency operation. In order to extract and utilize the favorable GaN material properties, however, there is still a lot to be investigated. Reduction of the gate leakage current is one of the key issues to be solved for their further improvement. A high work function metal such as Pt, Ir, Pd or Mo was inserted to the conventional Ni/Au Schottky contact to n-GaN and AlGaN/GaN epilayers, and the Schottky diodes were studied in detail with respect to the thermal annealing in nitrogen ambient. The electrical characteristics were found to be changed by the thermal treatment in each device. A drastic improvement was attained in the Ni/Pt(Ir)/Au system whereas degradation occurred in Ni/Mo/Au by RTA at 500 °C for 5 min. These phenomena were confirmed to be dependent on the work function of each inserted metal. The role of Ni in the Ni/Pt/Au system was also investigated, and it was found to be essential in obtaining better electrical performance in comparison with the diodes without Ni, such as Pt/Au or Ir/Au Schottky electrodes. The AlGaN/GaN HEMTs were fabricated using Ni/Pt/Au gate contacts. Reduction of the gate leakage current by as much as four orders of magnitude was successfully recorded by thermal annealing without degrading the transconductance of the transistor, and it was concluded that this technique was promising for high power AlGaN/GaN HEMT electronics.

Thermal annealing effects on Ni/Au based Schottky contacts on n-GaN and AlGaN/GaN with insertion of high work function metal

This paper presents the first linear bulk CMOS power amplifier (PA) targeting low-power fifth-generation (5G) mobile user equipment integrated phased array transceivers. The output stage of the PA is first optimized for power-added efficiency (PAE) at a desired error vector magnitude (EVM) and range given a challenging 5G uplink use case scenario. Then, inductive source degeneration in the optimized output stage is shown to enable its embedding into a two-stage transformer-coupled PA; by broadening interstage impedance matching bandwidth and helping to reduce distortion. Designed and fabricated in 1P7M 28 nm bulk CMOS and using a 1 V supply, the PA achieves +4.2 dBm/9% measured $P_{\text {out}}$ /PAE at −25 dBc EVM for a 250 MHz-wide 64-quadrature amplitude modulation orthogonal frequency division multiplexing signal with 9.6 dB peak-to-average power ratio. The PA also achieves 35.5%/10% PAE for continuous wave signals at saturation/9.6 dB back-off from saturation. To the best of the authors’ knowledge, these are the highest measured PAE values among published ${K}$ - and Ka -band CMOS PAs.

A Highly Efficient and Linear Power Amplifier for 28-GHz 5G Phased Array Radios in 28-nm CMOS

Boosted ultraviolet electroluminescence of InGaN/AlGaN quantum structures grown on high-index contrast patterned sapphire with silica array

Microelectronic devices, methods for packaging microelectronic devices, and methods for forming interconnects in microelectronic devices are disclosed herein. In one embodiment, a method comprises providing a microelectronic substrate having a front side and a backside. The substrate has a microelectronic die including an integrated circuit and a terminal operatively coupled to the integrated circuit. The method also includes forming a passage at least partially through the substrate and having an opening at the front side and/or backside of the substrate. The method further includes sealing the opening with a conductive cap that closes one end of the passage while another end of the passage remains open. The method then includes filling the passage with a conductive material.

Microelectronic devices and methods for forming interconnects in microelectronic devices

The invention is directed to a procedure for processing joints to be soldered, preferably printed circuit boards fitted with electric components, and an arrangement for executing this procedure, wherein the joints are subjected to plasma treatment before the soldering process. The joints may be subjected to plasma treatment separately or in the relative position necessary for the soldering process.

Procedure for processing joints to be soldered

A method of processing members to be joined by soldering, preferably of printed circuit boards equipped with electrical components, and a device for carrying out this method are disclosed, the members to be joined being subjected to a plasma treatment before the soldering operation. The members to be joined can alternatively be subjected to the plasma treatment separately or in the relative position required for the soldering operation. … …

Method and device for processing soldering joint partners

Red-emitting ridge waveguide lasers with integrated tenth order surface distributed Bragg reflector gratings were developed. The grating was implemented by the use of a BCl3-Ar-plasma, while the shape of the grating trench was controlled by additional He-backside cooling of the wafer. The devices exhibit longitudinal single mode operation up to 96 mW at 635.3 nm with a side mode suppression ratio of 18 dB and a good beam quality of M2<3. The spectrum is free of mode hops for a span of more than 55 pm.

96 mW longitudinal single mode red-emitting distributed Bragg reflector ridge waveguide laser with tenth order surface gratings.

Highly efficient polytype 4H silicon carbide (4H-SiC) p–n diodes for ultraviolet (UV) light detection have been fabricated, characterized, and exposed to high-intensity mercury lamp irradiation (up to 17 mW/cm2). The behavior of the photocurrent response under UV light irradiation using a low-pressure mercury UV-C lamp (4 mW/cm²) and a medium-pressure mercury discharge lamp (17 mW/cm²) has been studied. We report on long-term UV photoaging tests performed for up to 22 mo. Results demonstrate the robustness of SiC photodiodes against UV radiation. The devices under test showed an initial burn-in effect, i.e., the photocurrent response dropped by less than 5% within the first 40 h of artificial UV aging. Such burn-in effect under UV stress was also observed for previously available polytype 6H silicon carbide (6H–SiC) p–n photodetectors. After burn-in, no measurable degradation has been detected, which makes the devices excellent candidates for high irradiance UV detector applications.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/810710B9009ACF0A07EC287E7D3DD2E5/S0884291412002166a.pdf/div-class-title-highly-reliable-silicon-carbide-photodiodes-for-visible-blind-ultraviolet-detector-applications-div.pdf

Highly reliable silicon carbide photodiodes for visible-blind ultraviolet detector applications

This report describes the successful realization of high-quality semi-polar -GaN templates grown on 100 mm diameter r-plane patterned sapphire. Trench patterning is accomplished by plasma etching using a slanted SiNx mask that is formed by a resist-reflow process and subsequent dry etching. Epitaxial overgrowth by MOVPE is optimized with the aid of in situ monitoring to trace GaN coalescence behavior and surface morphology. Wafer curvature at growth temperature exceeds typical values of c-oriented GaN, whereas room-temperature bow is spherical and comparable to polar material. Morphological and structural properties compare well with published data on 2 in. substrates. Threading dislocation densities of about 2 × 108 cm−2 and basal stacking fault densities in the order of 1 × 103 cm−1 are deduced from cathodoluminescence studies. Low residual impurity concentrations ([O, Si] < 1 × 1017 cm−3) have been verified.

Wilfred John

Papers

Procedure for processing joints to be soldered

Method and device for processing soldering joint partners

96 mW longitudinal single mode red-emitting distributed Bragg reflector ridge waveguide laser with tenth order surface gratings.

Highly reliable silicon carbide photodiodes for visible-blind ultraviolet detector applications

Semi‐polar (112¯2)‐GaN templates grown on 100 mm trench‐patterned r‐plane sapphire