Semiconductor laser formed by layer intermixing

A method of making a multiple layer semiconductor device comprising the steps of:

• (a) providing a semiconductor substrate;
• (b) forming multiple layers over said substrate, in which at least one of said layers is doped and contains impurity atoms of a type and with a concentration adequate for impurity induced layer disordering of a limited amount of material;
• (c) intermixing said doped layer and its adjacent layers in selected lateral areas of said multiple layer structure by causing said impurities to diffuse in said selected areas but not to diffuse in other areas,
• wherein said lateral areas are selected by illumination with a scanned focused laser beam that raises the doped layer to a temperature above that at which intermixing takes place.

A method of making a multiple layer semiconductor device comprising the steps of:

• (a) providing a semiconductor substrate;
• (b) forming multiple layers over said substrate, in which at least one of said layers is doped and contains impurity atoms of a type and with a concentration adequate for impurity induced layer disordering of a limited amount of material;
• intermixing said doped layer and its adjacent layers in selected lateral areas of said multiple layer structure by causing said impurities to diffuse in said selected areas but not to diffuse in other areas,
• wherein said intermixing is obtained by thermally annealing.

A method of making a multiple layer semiconductor device comprising the steps of:

• (a) providing a semiconductor substrate;
• (b) forming multiple layers over said substrate, in which at least one of said layers is doped and contains impurity atoms of a type and with a concentration adequate for impurity induced layer disordering of a limited amount of material;
• intermixing said doped layer and its adjacent layers in selected lateral areas of said multiple layer structure by causing said impurities to diffuse in said selected areas but not to diffuse in other areas,
• wherein said intermixing is carried out by covering the body with a capping material in lateral areas where said doped layer is to be eliminated and thermally annealing the body, said capping material having a composition that acts as a source of vacancies and promotes vacancy-enchanced intermixing.

A method of making a multiple layer semiconductor device comprising the steps of:

• (a) providing a semiconductor substrate;
• (b) forming multiple layers over said substrate, in which at least one of said layers is doped and contains impurity atoms of a type and with a concentration adequate for impurity induced layer disordering of a limited amount of material;
• intermixing said doped layer and its adjacent layers in selected lateral areas of said multiple layer structure by causing said impurities to diffuse in said selected areas but not to diffuse in other areas,
• wherein said intermixing is induced by providing a pattern of reflective material covering the body in areas where selective intermixing is not wanted and irradiating the body with radiation to heat the doped layer in areas not covered by said reflective material.

A method of making a stacked active layer laser comprising the steps of:

• (a) providing a semiconductor body portion;
• (b) forming a lower cladding layer over said body portion;
• (c) forming a structure comprised of at least first and second separated active layers of respective first and second different energy band gaps over said lower cladding layer and an upper cladding layer over the first and second active layers;
• said structure having in said second active layer laterally spaced impurity induced intermixed and non-intermixed portions in a pattern coinciding with side-by-side first and second lasers for lasing, respectively, in shorter and longer wavelength regions, said impurity induced intermixed portion having a higher band gap than that of said first active layer,
• (d) said structure having been formed by thermal annealing under conditions such as to cause impurities to diffuse to and substantially intermix, and raise the band gap of, said second active layer portion at said first laser but not to diffuse to and substantially intermix said first active layer at said first laser or said second active layer at said second laser;
• (f) forming metal contacts on said structure so as to be able when voltages are applied to pass current individually through the first laser and second laser to form individually addressable side-by-side lasers lasing in shorter and longer wavelength regions, respectively.

A method of making a stacked active layer laser comprising the steps of:

• (a) providing a semiconductor body portion;
• (b) forming a lower cladding layer over said body portion;
• (c) forming a first structure comprised of at least first and second separated active layers of respective first and second different energy band gaps over said lower cladding layer;
• (d) said second active layer containing an impurity capable of inducing intermixing of the second active layer with adjacent body layers effectively eliminating said second active layer where intermixed;
• (e) thereafter thermally annealing said structure under conditions such as to cause selectively the impurities to diffuse to and induce intermixing with adjacent layers and thereby raise the band gap of portions of said second active layer at said first laser but not to diffuse to and substantially intermix said first active layer at said first laser or with portions of said second active layer at said second laser;
• (f) forming metal contacts over said structure so as to be able when voltages are applied to pass current individually through the first laser and the second laser to form individually addressable side-by-side lasers lasing in shorter and longer wavelength regions, respectively.

A method of making an index-guided III-V semiconductor laser by impurity-induced layer disordering comprising the steps of:

• (a) providing a semiconductor body portion;
• (b) forming a lower cladding layer over said body portion;
• (c) forming an active layer over said lower cladding layer and an upper cladding layer over the active layer;
• said structure having in said active layer laterally spaced impurity induced intermixed first portions flanking a non-intermixed impurity-doped second portion, said impurity induced intermixed first portions having a higher band gap than that of said non-intermixed second portion,
• (d) said structure having been formed by thermal annealing under conditions such as to cause impurities doping the active layer to diffuse to and substantially intermix, and raise the band gap of, said first portions but not to diffuse to and substantially intermix said second portion and third portions of said upper cladding layer overlying the first portions.