Optimization and characterization of remote plasma-enhanced chemical vapor deposition silicon nitride for the passivation of p-type crystalline silicon surfaces Plasma enhanced chemical vapor deposition and characterization of boron nitride gate insulators on InPRemote plasma enhanced chemical vapor deposition of silicon nitride on III-V semiconductors: Xray photoelectron spectroscopy studies of the interface J.

Experimental plasma etching apparatus and methods u t i l i z i n g BC.13 etch gas have been developed f o r t h e a c c u r a t e p a t t e r n i n g of t h i n A 1 and A1-Si a l l o y m e t a l l i z a t i o n as used i n i n t e g r a te d c i r c u i t f a b r i c a t i o n . A two micron linewidth capability has been achieved for the patterning of 0.5 micron thick m e t a l l i z a t i o n on three inch diameter wafers with p o s i t i v e a n d n e g a t i v e p h o t o r e s i s t e t c h masks as t h i n as 25008. Etchrates of 500 t o 1000 8/min. are t y p i c a l , and t h e r e i s n e g l i g i b l e e t c h i n g of b o t h t h e p h o t o r e s i s t and the underlying Si02 l a y e r s . The process is CMOS compatible, yielding threshold voltage shift and temperature-bias s t a b i l i t y s p e c i f i c a t i o n s o f less than 20.050 v o l t s t h a t a r e c o m p a r a b l e t o t h o s e f o r wet chemically etched devices.

Auger analysis of oxidized GaAs surfaces, heat treated in vacuo, has been used to establish an accurate value for the oxide desorption temperature Tox. Major differences are found in the value of Tox for the surface oxides produced by thermal and ozone oxidation: 582±1 °C and 638±1°C, respectively. These temperature differences are also confirmed by reflection high-energy electron diffraction observations of the thermal cleaning of GaAs substrates prior to epitaxial growth in a molecular beam epitaxy system. It is suggested that the measured temperatures can be used in establishing appropriate growth conditions for ‘‘indium-free’’ GaAs substrates during molecular beam epitaxial growth.

The formation of sacrificial oxides on GaAs is a well established procedure in the preparation of in situ cleaned substrates for epitaxial growth. Oxides formed from ozone exposure promise a more controlled alternative to thermal and air formed oxides. This paper reports on a study of the composition and structures of oxides on GaAs(100) surfaces and, in addition, examines the persistence of carbon-containing species at the oxide surface and oxide–semiconductor interface. X-ray photoelectron spectroscopy (XPS) was used in a high spectral resolution mode, to distinguish between the different oxide phases formed. Surfaces oxidized under ozone for 10–30 min had Ga/As oxide ratios close to unity. By contrast, acid treated, DI water rinsed surfaces exposed to air produce oxides rich in either Ga or As depending on conditions. Heating of the ozone-produced oxide to ≥600 °C results in sequential decomposition of As2O5, As2O3, and Ga2O3. Oxide layers produced by short-term ozone exposures were analyzed by angle-resolved XPS. A 10 min exposure produced an oxide of 2.0 nm thickness. Surface carbon-containing contaminants were removed to a level ≤0.2 monolayer by heating the specimen to 400 °C in vacuum (base pressures of 2×10−8 Pa). Surfaces heated to ≥600 °C to desorb all oxides, also showed no evidence of carbon-containing species and the As/Ga ratio was unity.

GaAs metal insulator semiconductor capacitors and high transconductance metal insulator semiconductor field effect transistorsPassivation of both cleaved GaAs͑110͒ facets and wafers ͑both n and p types͒ was performed with different surface treatments including HF-etch of native oxide, passivation with an ammonium sulfide solution, passivation with hydrogen polysulfide, and passivation with a Si/S, Ge/S, or Si/Ge/S interface control layer. The interface state density was measured with capacitance-voltage ͑CV͒ measurements of metal-insulator-semiconductor capacitors fabricated on the passivated surfaces using remote plasma deposited silicon nitride as gate insulator. The interface structures of the capacitors were analyzed by x-ray absorption near-edge structure spectroscopy and x-ray photoemission spectroscopy. It was found that, while the passivation procedures with the sulfur compounds or a Si/S interface control layer did improve the CV data when compared with the HF oxide etch, the Si/Ge/S multilayer passivation technique led to the best CV results. By comparing the quasistatic and high frequency ͑1 MHz͒ CV data, we found that the minimum interface state density of the fabricated capacitors was about 10 12 eV Ϫ1 cm Ϫ2 . The results were compared with those obtained from GaAs͑100͒ and the difference was addressed with respect to the surface geometry and the electronic structures.