Method and apparatus for preparing nitride semiconductor surfaces
AssigneeArizona Board of Regents
InventorsR. Bruce Doak, Christopher T. Burns, Dirk C. Jordan
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Abstract
Semiconductor nitride layers are produced using a corona discharge supersonic free-jet source producing an activated nitrogen molecule beam impacting a semiconductor substrate in the presence of a group III metal or impacting an oxide layer on a semiconductor substrate. The activated nitrogen molecules are of the form N2A3Σu+. Apparatus for producing the nitride layer on the substrate includes the corona discharge free-jet source, a skimmer to collimate the N2 beam and succeeding stages interconnected by collimators and evacuated to draw off background gases.
Claims24
An apparatus for producing nitride films comprising:
- (a) a pair of corona-discharge producing electrodes,
- (b) a nitrogen delivery path leading to a nozzle at which the electrodes produce a corona discharge,
- (c) means to locate a substrate along the nitrogen delivery path downstream of the location at which the electrodes produce the corona discharge for deposition thereon of nitrogen activated by the corona discharge at a location sufficiently distant from the corona-discharge producing electrodes such that essentially the only activated nitrogen impingent on the substrate is N2A3Σu+, and
- (d) the distance within the apparatus from the corona-discharge producing electrodes to the means to locate a substrate providing a transit time of the nitrogen traveling therebetween along the nitrogen delivery path exceeding the lifetime of activated nitrogen in states other than N2A3Σu+, whereby those states are effectively filtered out of nitro en reaching the location of the means to locate a substrate.
Apparatus for producing a film on a semiconductor substrate comprising:
- (a) means for establishing a vacuumized environment,
- (b) means for establishing a corona discharge in the vacuumized environment,
- (c) means for creating a flow of nitrogen gas into the corona discharge and a supersonic jet of diatomic, activated metastable nitrogen molecules from the corona discharge,
- (d) means for collimating the jet of nitrogen molecules, and
- (e) means for locating a target semiconductor substrate in the path of the collimated jet of nitrogen particles at a distance from the means for establishing a corona discharge such that substantially only diatomic nitrogen molecules of the form N2A3Σu+ and N2X1Σg+ are present at that distance, and
- (f) the distance within the apparatus form the corona-discharge producing electrodes to the means for locating a target semiconductor substrate providing a transit time of the nitrogen traveling therebetween in the collimated jet that exceeds the lifetime of activated nitrogen present in the jet in states other than N2A3Σu+, whereby activated nitrogen in those states are effectively filtered out of the nitrogen present at the means for locating the target semiconductor substrate by their conversion to the A3Σu+ state.
An apparatus for producing a dielectric insulator film comprising:
- (a) at least one corona-discharge producing electrode pair,
- (b) at least one source of a pressurized reagent gas,
- (c) at least one path of reagent gas flow to at least one nozzle proximate the tip of one electrode of the at least one pair and in the region of corona discharge,
- (d) a reduced pressure location at an outlet of the nozzle into which the reagent gas emerges as a supersonic jet of activated reagent molecules,
- (e) a skimmer downstream of the nozzle in the direction of flow of the supersonic jet,
- (f) a substrate location downstream of the skimmer, in operation locating a substrate for formation thereon a dielectric film composed at least in part of the reagent, and
- (g) a supersonic jet expansion region between the skimmer and the substrate location of a length to effect filtering out of relatively short-lived excited states of the reagent gas moving in the supersonic jet toward the substrate location.
Dependencies are inferred from the claim text.