Yi Wu

This paper presents a 60-GHz CMOS artificial magnetic conductor (AMC) on-chip 2×2 monopole - antenna phased array RF receiving system with integrated variable-gain low-noise amplifier (VGLNA) and 360° phase shifter ( PS ). With the AMC structure, the radiation efficiency and power gain of the antenna increases from 6% to 15% and from -9 to -5 dBi at 60 GHz, respectively. In VG-LNA design, variable gain is achieved by a current-steering structure and low phase variation is achieved by a body-floating technique. The proposed 360° phase shifter is implemented by cascading a 180° reflection-type and a 180° switch-type phase shifters. The measurement results show that a phase control range of 360° with a gain variation of 3.7 dB can be achieved. In terms of gain controlling capability, a 11.3-dB gain control range with a 13.5° phase variation is obtained. On-wafer beam steering measurement shows that the main beam can scan to ±25°. The total power consumption is 75 mW from a 1.5 V power supply. The chip size is 3.1 × 3.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

This work studied the hydrogen and oxygen plasma effects on the resistivity, effective free carrier concentration, and mobility of As + - and BF 2 + -doped polycrystalline silicon (polysilicon) thin films of various thicknesses. It was found that the resistivity of a polysilicon thin film increased with the decrease of the thickness of the film. This was mainly due to the decrease of effective carrier concentration and the mobility through the decrease of the grain size since the thickness limited regrowth of the film. The hydrogen and/or oxygen plasma treatment decreased the effective carrier concentration of the film through the neutralization of boron and arsenic ions. This effect was more evident for the thinner (&lt;60 nm) film. The plasma treatment also decreased the mobility of the film, unless the thickness of the film was thinner than 50 nm, for which, the mobility instead increased since the plasma passivation effect became dominant.

As continue shrinking of microelectronic device features, removal of nano-particle contaminations is becoming a major challenge in semiconductor manufacturing. After effective wafer cleaning, high particles removal efficiency must be achieved without substrate loss or damage to high aspect ratio structures. In this work, a novel dual-fluid spray nozzle was tested. The cleaning performance with control to normal dispense nozzle was investigated. Also, structural damage tests were carried out on poly-gate-stack line pattern wafers, and compared to the results acquired with megasonic cleaning. The results showed potential applications of such dual-fluid spray nozzle in sub-65nm devices manufacturing.

With the increase of the wafer size, it becomes more and more challenging to control the etching rate and etching non-uniformity precisely in the wet process of semiconductor manufacturing. In this paper, the effects of the DHF (diluted hydrofluoric acid) starting dispensing point, the dispensing time, and the wafer clean time on etching rate and non-uniformity of the silicon oxide wafer were investigated. The results indicated that the first reaction of DHF with silicon wafer surface plays an important role to the final etching rate and non-uniformity. Based on the analysis, a new method of zero lag dispense was proposed and tested to reduce the non-uniformity of etching. The method uses a special dispensing device to inject DHF on the surface instantaneously and uniformly before it is dispensed from the swinging nozzle. The non-uniformity within a wafer reduces to 1.8% under DHF process (1:220, 20°C, 60s).