Hydrogenation and Defect Creation in GaAs-Based Devices During High Density Plasma Processing

1998 ◽  
Vol 510 ◽  
Author(s):  
T. Maeda ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  

AbstractThe effects of Inductively Coupled Plasma (ICP) and Electron Cyclotron Resonance (ECR) H2 plasmas on GaAs metal semiconductor field effect transistors (MESFETs), high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs) have been measured as a function of ion flux, ion energy and process pressure. The chemical effects of hydrogenation have been compared to direct physical bombardment by Ar plasmas under the same conditions. Si dopant passivation in MESFETs and HEMTs and C base-dopant passivation in HBTs produces much larger changes in sheet resistance, breakdown voltage and device gain or transconductance than Ar ion bombardment and suggests that H2-containing plasma chemistries (CH4/H2 for semiconductor etching, SiH4 for dielectric deposition, CHF3 for dielectric etching) should be avoided, or at least the exposure of the surface minimized. In some cases the device degradation is less for higher source power conditions, due to the suppression of cathode dc self-bias and hence ion energy.

1999 ◽  
Vol 595 ◽  
Author(s):  
A.P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X.A. Cao ◽  
H. Cho ◽  
...  

AbstractThe effects of dc chuck self-bias and high density source power (which predominantly control ion energy and ion flux, respectively) on the electrical properties of n-GaN Schottky diodes exposed to Inductively Coupled Plasma of Cl2/Ar were examined. Both parameters were found to influence the diode performance, by reducing the reverse breakdown voltage and Schottky barrier height. All plasma conditions were found to produce a nitrogen-deficient surface, with a typical depth of the non-stoichiometry being ∼500 Å. Post-etch annealing was found to partially restore the diode characteristics.


2000 ◽  
Vol 5 (S1) ◽  
pp. 831-837
Author(s):  
A.P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X.A. Cao ◽  
H. Cho ◽  
...  

The effects of dc chuck self-bias and high density source power (which predominantly control ion energy and ion flux, respectively) on the electrical properties of n-GaN Schottky diodes exposed to Inductively Coupled Plasma of Cl2/Ar were examined. Both parameters were found to influence the diode performance, by reducing the reverse breakdown voltage and Schottky barrier height. All plasma conditions were found to produce a nitrogen-deficient surface, with a typical depth of the non-stoichiometry being ∼ 500 Å. Post-etch annealing was found to partially restore the diode characteristics.


1998 ◽  
Vol 512 ◽  
Author(s):  
J. J. Wang ◽  
Hyun Cho ◽  
E. S. Lambers ◽  
S. J. Peartont ◽  
M. Ostling ◽  
...  

ABSTRACTA parametric study of the etching characteristics of 6H p+ and n+ SiC and thin film SiC0.8N0.2 in Inductively Coupled Plasma NF3/O2 and NF3/Ar discharges has been performed. The etch rates in both chemistries increase monotonically with NF3 percentage and rf chuck power reaching 3500Å·min−1 for SiC and 7500 Å·min−1 for SiCN. The etch rates go through a maximum with increasing ICP source power, which is explained by a trade-off between the increasing ion flux and the decreasing ion energy. The anisotropy of the etched features is also a function of ion flux, ion energy and atomic fluorine neutral concentration. Indium-tinoxide( ITO) masks display relatively good etch selectivity over SiC(maximum of 70:1) while photoresist etches more rapidly than SiC. The surface roughness of SiC is essentially independent of plasma composition for NF3/O2 discharges, while extensive surface degradation occurs for SiCN under high NF3:O2 conditions. The high ion flux available in the ICP tool allows etching even at very low dc self-biases, ≤ −10V, leading to very low damage pattern transfer.


2018 ◽  
Vol 37 (6) ◽  
pp. 545-550
Author(s):  
Mikhail Isupov ◽  
Vadim Pinaev ◽  
Daria Mul ◽  
Natalia Belousova

AbstractAn experimental investigation of plasma-assisted nitriding of austenitic stainless steel AISI 321 in a low-pressure (7 Pa), low-frequency (50–100 kHz) nitrogen inductively coupled plasma enhanced with ferromagnetic cores has been performed at the temperatures of 470–625 °C, sample biases of ‒500–‒750 V, current densities on the sample surface of 1.2–3.3 mA/cm2 and nitriding times of 20 and 60 min. It is found that even the short (20 min) ion-plasma treatment results in the formation of nitrided layers with the thickness of up to 40 μm and microhardness of up to 9 GPa.The high speed of nitriding can be explained as a result of the joint action of high ion flux density and high ion energy on the sample surface.


1991 ◽  
Vol 241 ◽  
Author(s):  
R. A. Metzger ◽  
A. S. Brown ◽  
R. G. Wilson ◽  
T. Liu ◽  
W. E. Stanchina ◽  
...  

ABSTRACTAlInAs and GaInAs lattice matched to InP and grown by MBE over a temperature range of 200 to 350°C (normal growth temperature of 500°C) has been used to enhance the device performance of inverted (where the donor layer lies below the channel) High Electron Mobility Transistors (HEMTs) and Heterojunction Bipolar Transistors (HBTs), respectively. We will show that an AlInAs spacer grown over a temperature range of 300 to 350°C and inserted between the AlInAs donor layer and GaInAs channel significantly reduces Si movement from the donor layer into the channel. This produces an inverted HEMT with a channel charge of 3.0×1012 cm−2 and mobility of 9131 cm2/V-s, as compared to the same HEMT with a spacer grown at 500 °C resulting in a channel charge of 2.3×1012 cm−2 and mobility of 4655 cm2/V-s. We will also show that a GaInAs spacer grown over a temperature range of 300 to 350°C and inserted between the AlInAs emitter and GalnAs base of an npn HBT significantly reduces Be movement from the base into the emitter, thereby allowing higher Be base dopings (up to 1×1020 cm−3) confined to 500 Å base widths, resulting in an AlInAs/GaInAs HBT with an fmax of 73 GHz and ft of 110 GHz.


1997 ◽  
Vol 70 (18) ◽  
pp. 2410-2412 ◽  
Author(s):  
F. Ren ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
C. Constantine ◽  
...  

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