US3901738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion implanted junction laser and process for making same
Assignee: Raytheon Co
•
Filing: 1974-05-13
•
Granted: 1975-08-26
•
Expires: 1994-05-13
Abstract
Abstract There is disclosed a process of ion implantation doping of a semiconductor followed by application of a surface passivating layer and annealing to produce therein shallow junctions the actual depth of which can be accurately controlled either as a function of the conditions of the annealing which causes diffusion of the implanted ions primarily into the semiconductor to form a junction at a depth which is proportional to the square root of the time of annealing for a given temperature where an ion such as Zn is used which will diffuse, or as a function of the energies and doses of a plurality of implantation steps where an ion such as Be which will not diffuse during annealing, is used. The first process was, for example, used as a doping technique to fabricate an injection laser in GaAs by using the Zn atom as a dopant resulting in a junction at a depth of one micron from the surface. At 77* K the threshold current density of the junction required to produce lasing was 140 amps/cm2. The second process was, for example, used to fabricate an injection laser in GaAs with its junction at 1.6 microns below the surface using four different sequential implantation steps. Such a laser can be formed as a discrete component or it can be formed integrally with a waveguide and a utilization circuit. There is shown, by way of example, the combination of a laser, a waveguide and a photodetector formed integrally in a chip to produce an optoisolator.
Inventors
- 👤 Robert G Hunsperger
- 👤 Ogden J Marsh
- 👤 Michael K Barnoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:50
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/21; H10F; H10F99/00; H10H; H10H20/00; H10H20/80; H10P30/202; H10P30/206; H10P30/28; Y; Y10; Y10S; Y10S148/00; Y10S148/056
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
96 words
IN A SEMICONDUCTOR INJECTION LASER OF THE TYPE HAVING A P-N JUNCTION FORMED IN A SEMICONDUCTOR BODY, MEANS PROVIDING FEEDBACK OF LIGHT EMITTED FROM SAID LASER JUNCTION AND MEANS TO SUPPLY PUMPING ENERGY TO SAID LASER, SAID LASER BEING FURTHER CHARACTERIZED BY: SAID P-N JUNCTION BEING FORMED BY IMPLANTING DOPANT IONS INTO A SURFACE OF SAID SEMICONDUCTOR BODY, FORMING A PASSIVATING LAYER ON SAID SURFACE AND ANNEALING SAID IMPLANTED BODY AT A TEMPERATURE AND DURING A TIME PRESELECTED TO DIFFUSE SAID IMPLANTED IONS TO FORM A UNFORM PLANAR JUNCTION AT A PREDETERMINED DEPTH BELOW SAID SURFACE
Claim 2
Dependent Claim
96 words
IN A SEMICONDUCTOR INJECTION LASER OF THE TYPE HAVING A P-N JUNCTION FORMED IN A SEMICONDUCTOR BODY, MEANS PROVIDING FEEDBACK OF LIGHT EMITTED FROM SAID LASER JUNCTION AND MEANS TO SUPPLY PUMPING ENERGY TO SAID LASER, SAID LASER BEING FURTHER CHARACTERIZED BY: SAID P-N JUNCTION BEING FORMED BY IMPLANTING DOPANT IONS INTO A SURFACE OF SAID SEMICONDUCTOR BODY, FORMING A PASSIVATING LAYER ON SAID SURFACE AND ANNEALING SAID IMPLANTED BODY AT A TEMPERATURE AND DURING A TIME PRESELECTED TO DIFFUSE SAID IMPLANTED IONS TO FORM A UNFORM PLANAR JUNCTION AT A PREDETERMINED DEPTH BELOW SAID SURFACE
Claim 3
Dependent Claim
32 words
A laser as in claim 1 wherein said predetermined depth of said junction below said surface is proportional to the square root of said time of annealing for a given fixed temperature.
Claim 4
Dependent Claim
22 words
A laser as in claim 1 wherein said predetermined depth below said surface is of the order of magnitude of one micron.
Claim 5
Dependent Claim
20 words
A laser as in claim 1 wherein said semiconductor body is n-type GaAs and said dopant ions are Zn .
Claim 6
Dependent Claim
61 words
A laser as in claim 1 wherein said semiconductor body is tellurium doped (1 X 1018/cm3) <100> n-type GaAs, said dopant ions are Zn with a dose of 1016/cm2 implanted at an energy of 300KeV, said passivating layer is SiO2, said annealing is for three hours at 900*C, and the depth of said junction below said surface is substantially one micron.
Claim 7
Dependent Claim
126 words
A process of forming a shallow p-n junction at a controlled depth in a semiconductor body of a first conductivity type comprising the steps of: a. irradiating said semiconductor body with a beam of dopant ions to implant said ions in the irradiated surface of said body to form a layer of a second conductivity type opposite in polarity to said first conductivity type; b. coating said ion implanted surface of said semiconductor body with a layer of passivating material; and c. annealing said semiconductor body at a temperature sufficient to reduce the concentration of nonradiative centers to the point where efficient lasing and optical emission from said junction can occur; and d. controlling the depth of said junction below the surface of said semiconductor body.
Claim 8
Dependent Claim
126 words
A process of forming a shallow p-n junction at a controlled depth in a semiconductor body of a first conductivity type comprising the steps of: a. irradiating said semiconductor body with a beam of dopant ions to implant said ions in the irradiated surface of said body to form a layer of a second conductivity type opposite in polarity to said first conductivity type; b. coating said ion implanted surface of said semiconductor body with a layer of passivating material; and c. annealing said semiconductor body at a temperature sufficient to reduce the concentration of nonradiative centers to the point where efficient lasing and optical emission from said junction can occur; and d. controlling the depth of said junction below the surface of said semiconductor body.
Claim 9
Dependent Claim
50 words
A process as in claim 6 wherein said dopant ions diffuse during said annealing and wherein said depth of said junction is controlled by preselecting the time duration of said annealing to have a magnitude the square root of which is linearly proportioned to the desired depth of said junction.
Claim 10
Dependent Claim
47 words
A process as in claim 6 wherein said dopant ions do not diffuse significantly during said annealing and wherein said depths of said junction is controlled by sequentially implanting said ions in a plurality of implants each being of a different dose and at a different energy.
Claim 11
Dependent Claim
37 words
A process as in claim 6 and further including the step of removing said passivating layer from said annealed semiconductor body and applying ohmic contacts thereto on opposite sides of said junction to form a junction diode.
Claim 12
Dependent Claim
96 words
In a process of forming a p-n junction in a semiconductor body of a first conductivity type the improvement comprising: a. irradiating a surface of said body with a dose of dopant ions of a second conductivity type of opposite polarity to said first type; b. applying a layer of passivating material to said irradiated surface to form an encapsulated source of dopant ions; and c. annealing said irradiated semiconductor body to cause said dopant ions to diffuse primarily into said semiconductor body, for a distance proportional to the square root of the time of annealing.
Claim 13
Dependent Claim
96 words
In a process of forming a p-n junction in a semiconductor body of a first conductivity type the improvement comprising: a. irradiating a surface of said body with a dose of dopant ions of a second conductivity type of opposite polarity to said first type; b. applying a layer of passivating material to said irradiated surface to form an encapsulated source of dopant ions; and c. annealing said irradiated semiconductor body to cause said dopant ions to diffuse primarily into said semiconductor body, for a distance proportional to the square root of the time of annealing.
Claim 14
Dependent Claim
108 words
In a semiconductor injection laser of the type having a p-n junction formed in a semiconductor body, means providing feedback of light emitted from said laser junction and means to supply pumping energy to said laser, said laser being further characterized by: said p-n junction being formed by implanting dopant ions into a surface of said semiconductor body, forming a passivating layer on said surface and annealing said implanted body at a temperature and during a time sufficient to electrically activate the implanted ions, and the depth of said junction below said surface being controlled to form a uniform planar junction at a predetermined depth below said surface.
Claim 15
Dependent Claim
108 words
In a semiconductor injection laser of the type having a p-n junction formed in a semiconductor body, means providing feedback of light emitted from said laser junction and means to supply pumping energy to said laser, said laser being further characterized by: said p-n junction being formed by implanting dopant ions into a surface of said semiconductor body, forming a passivating layer on said surface and annealing said implanted body at a temperature and during a time sufficient to electrically activate the implanted ions, and the depth of said junction below said surface being controlled to form a uniform planar junction at a predetermined depth below said surface.
Claim 16
Dependent Claim
62 words
A device as in claim 11 wherein said semiconductor body is GaAs, said dopant ions are zinc and wherein said depth of said junction below said surface is controlled by annealing said implanted body at a temperature and during a time preselected not only to electrically activate the implanted ions but also to diffuse said implanted ions to said controlled junction depth.
Claim 17
Dependent Claim
45 words
A device as in claim 11 wherein said semiconductor body is GaAs, said dopant ions are beryllium and wherein said depth of said junction below said surface is controlled by sequentially applying a plurality of implantations of beryllium ions at differing doses and differing energies.
Claim 18
Dependent Claim
34 words
A laser as in claim 11 wherein said means providing feedback of light comprises diffraction grating means on said surface of said semiconductor body and said pumping energy supplied to said laser is electrical.
Claim 19
Dependent Claim
37 words
A laser as in claim 11 wherein said laser is formed integrally with a waveguide for receiving the light output of said laser, said laser and said waveguide comprising an integrated optical circuit in said semiconductor body.
Claim 20
Dependent Claim
76 words
A laser as in claim 11 wherein said laser is formed integrally with a waveguide for receiving the light output of said laser, said laser and said waveguide comprising an integrated optical circuit in said semiconductor body, said means providing feedback of light comprises diffraction grating means on the surface of said semiconductor body, and said pumping energy supplied to said laser is electrical energy supplied through ohmic contacts on opposite surfaces of said semiconductor body.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |