Compound semi-conductors and controlled doping thereof
AssigneeOhio Aerospace Institute
InventorsDavid J. Larkin, Philip G. Neudeck, J. Anthony Powell, Lawrence G. Matus
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Abstract
A method of controlling the amount of impurity incorporation in a crystal grown by a chemical vapor deposition process. Conducted in a growth chamber, the method includes the controlling of the concentration of the crystal growing components in the growth chamber to affect the demand of particular growth sites within the growing crystal thereby controlling impurity incorporation into the growth sites.
Claims52
A method of regulating an amount of at least one non-crystal element deposited in a given growth area of a single crystal formed from at least two crystal elements as said crystal is grown in a growth chamber, said crystal elements comprising a first crystal element and a second crystal element, said crystal having at least two crystal growing sites wherein said first crystal element is deposited in a first growth site and said second crystal element is deposited in a second element growth site, said at least one non-crystal element being competitive for said first site, said method comprising the steps of:
- a. selecting an amount of said non-crystal element to be deposited in said given growth area;
- b. selecting a ratio of said first crystal element to said second crystal element, said ratio being dependent on said selected amount of said non-crystal element to be deposited in said given growth area;
- c. flowing a controlled amount of at least one gaseous crystal element compound through said chamber to grow said crystal, said controlled amount corresponding to said selected ratio of said first crystal element to said second crystal element in said growth chamber, and each of said element compound including at least one of said crystal element;
- d. selecting a new amount of said non-crystal element to be deposited in said given growth area;
- e. selecting a new ratio of said first crystal element to said second crystal element to obtain said new amount of said non-crystal element to be deposited in said given growth area;
- and,
- f. changing said ratio of said crystal elements in said growth chamber during the growing of said crystal to regulate said amount of said at least one non-crystal element deposited in said competitive crystal growth site at said growth area to obtain said new amount of said non-crystal element being deposited in said given growth area.
A method of growing crystals containing a non-crystal element, of a concentration of less than about 1.0.times.10.sup.16 cm.sup.-3, said crystal formed from at least two crystal elements being grown by a process conducted in a growth chamber, said crystal having at least two growth sites and said non-crystal element competitive for a growth site, said method comprising:
- a) identifying said growth site said non-crystal element is competitive for;
- b) identifying the crystal element which deposits in said growth site said non-crystal element is competitive for;
- c) selecting a crystal element ratio of said two crystal elements which contains an amount of the competing crystal element which will compete with said non-crystal element during said crystal growth to form said crystal with said selected amount of non-crystal element;
- and
- d) flowing said selected amount of crystal elements into said growth chamber to grow said crystal.
A method containing a non-crystal element concentration of greater than about 1.times.10.sup.19 cm.sup.-3, said crystal formed from at least two crystal elements being grown by a process conducted in a growth chamber, said crystal having at least two growth sites and said non-crystal element competitive for a growth site, said method comprising:
- a) identifying said growth site said non-crystal element is competitive for;
- b) identifying the crystal element which deposits in said growth site said non-crystal element is competitive for;
- c) selecting a crystal element ratio of said two crystal elements which contains an amount of the competing crystal element which will compete with said non-crystal element during said crystal growth to form said crystal with said selected amount of non-crystal element;
- and
- d) flowing said selected amount of crystal elements into said growth chamber to grow said crystal.
A method of growing a crystal containing a selected ratio of at least one n-type dopant and at least one p-type dopant, said crystal formed from at least two crystal elements being grown by a process conducted in a growth chamber, said crystal having at least two growth sites and said at least one n-type dopant primarily competitive for a n-type growth site and said at least one p-type dopant primarily competitive for a p-type growth site, said method comprising of:
- a) identifying said crystal element which primarily deposits in said p-type growth site;
- b) identifying said crystal element which primarily deposits in said n-type growth site;
- c) selecting said ratio of n-type dopant to said p-type dopant incorporation;
- d) selecting an element ratio which contains a certain amount of said n-type growth site crystal element to said p-type growth site crystal element to obtain said amount of n-type dopant and p-type dopant to be deposited in said crystal during crystal growth, said ratio being dependent on said selected ratio of said n-type to p-type dopant ratio;
- and
- e) flowing said at least two crystal elements into said growth chamber in said selected ratio amounts.
A method of growing single crystals containing a selected concentration of a non-crystal element, said single crystal formed from at least two crystal elements being grown by a process conducted in a growth chamber, said single crystal having at least two growth sites and said non-crystal element competitive for a growth site, said method comprising:
- a) identifying said growth site said non-crystal element is competitive for;
- b) identifying the crystal element which deposits in said growth site said non-crystal element is competitive for;
- c) controlling a crystal element ratio which contains a certain amount of the competing crystal element which will compete with said non-crystal element during said crystal growth so that .gtorsim.1.0.times.10.sup.19 cm.sup.-3 of non-crystal element is incorporated in said crystal.
A method of growing single crystals containing a selected concentration of non-crystal element, said single crystal formed from at least two crystal elements being grown by a process conducted in a growth chamber, said single crystal having at least two growth sites and said non-crystal element competitive for a growth site, said method comprising:
- a) identifying said growth site said non-crystal element is competitive for;
- b) identifying the crystal growth which deposits in said growth site said non-crystal element is competitive for;
- c) controlling a crystal element ratio which contains a certain amount of the competing crystal element which will compete with said non-crystal element during said crystal growth so that .ltorsim.1.0.times.10.sup.15 cm.sup.-3 of non-crystal element is incorporated in said single crystal.
A method of selecting the amount of a dopant element deposited in a given growth area of a single crystal and reducing the amount of a contaminant element deposited in a given growth area of the single crystal, said single crystal formed from at least two crystal elements as said crystal is grown at an area by a CVD process conducted in a growth chamber, said crystal elements comprising a first crystal element and a second crystal element, said single crystal having at least two crystal growing sites wherein said first crystal element is deposited in a first growth site and said second crystal element is deposited in a second element growth site, said dopant element being competitive for at least one of said first and second growth sites, said contaminant element being competitive for a growth site other than said growth site of said dopant element, said method comprising the steps of:
- a) identifying said growth site said dopant element is competitive for;
- b) identifying said growth site said contaminant element is competitive for;
- c) identifying a first crystal element which deposits in said growth site said dopant element is competitive for;
- d) identifying a second crystal element which deposits in said growth side said contaminant element is competitive for;
- e) selecting a ratio of said two crystal elements to obtain said selected amount of said dopant element deposited in said competitive crystal growth site and simultaneously reducing said amount of said contaminant element deposited in said competitive crystal growth site;
- and
- f) flowing said selected ratio of crystal elements into said growth.
Dependencies are inferred from the claim text.