Motorola Corporation

Other

Herng-Der Chiou

Ping-chang Lue

Tien-Yu Tom Lee

Earl D Fuchs

James B Hall

Geoffrey J Crabtree

Gary G Ehlenberger

Lawrence Duane Mason

Raul P Torres

A single crystal ingot (10) is grown by first inserting a single crystal seed (14) into a melt (11) and pulling the seed (14) at a high pulling rate to grow a single crystal neck (15). The pulling rate is then altered to grow an overhang (18) with a diameter greater than that of the single crystal neck (15). An elongated body (19) is formed below the overhang (18) by adjusting the pulling rate. A multi-arm fixture (30) grabs the overhang (18) to alleviate the tensile and torsional stresses in the single crystal neck (15) that may be caused by the weight and the rotational motion of the single crystal ingot (10).

Single crystal ingot and method for growing the same

Trench structures (12,32,35,46) are formed in single crystal silicon substrates (10,30) that have either a (110) or (112) orientation. A selective wet etch solution is used that removes only the exposed portions of the single crystal silicon substrates (10,30) that are in the (110) or (112) crystal planes. The trench structures (12,32,35,46) are defined by the {111} crystal planes in the single crystal silicon substrate (10,30) that are exposed during the selective wet etch process. Trench structures (32,35) can be formed on both sides of a single crystal silicon substrate (30) to form an opening (34). Opening (34) can be used as an alignment mark to align front side processing to backside and vice versa. Trench structures can also be use to form a microstructure (41,61) for a sensor (40,60).

Method of etching a trench into a semiconductor substrate

A seed (22) is formed to have a �110! direction (24) that is at an angle (26) to the pull direction (23) used for growing a semiconductor ingot (36). Dislocations (34) in the ingot (36) terminate on the surface of the neck (37) of the ingot, and do not propagate into the body (38) of the ingot (36).

Method of forming semiconductor material

A method for fabricating semiconductor substrates with resistivity below 0.02 ohm-cm is provided. This low resistivity is achieved by doping a silicon melt with a phosphorus concentrations above 1.times.10.sup.18. The silicon melt is also doped with a germanium concentration that is 1.5 to 2.5 times that of the phosphorus concentration and a stress and dislocation free crystalline boule is grown. Phosphorus in high concentrations will induce stress in the crystal lattice due to the difference in the atomic radius of silicon atoms versus phosphorus atoms. Germanium compensates for the atomic radius mismatch and also retards the diffusion of the phosphorus as the diffusion coefficient remains relatively constant with a doping of 1.times.10.sup.18 to 1.times.10.sup.21 atoms per cm.sup.3. This will retard phosphorus from diffusing into an overlying epitaxial layer and retard other layers formed on the substrate from being auto-doped.

Semiconductor device formed on a highly doped N+ substrate

A method of growing semiconductor crystals including inserting a single crystal seed (14) of a semiconductor material into a melt (12) and pulling the seed (14) at a first rate to gradually grow an elongated, single crystal first neck (15), altering the pulling rate to a second rate, slower than the first rate, to grow a shoulder (17) on the first neck (15) with a diameter greater than the first neck (15), continuing to pull at the second rate to form a second neck (18) with a diameter equal to the diameter of the shoulder (17), and altering the pulling rate to a third rate, slower than the second rate, to grow a single crystal elongated body (20) of the semiconductor material.

Semiconductor crystal growth method

A solid metal-gettering material is used between walls of a double-walled processing chamber, such as a furnace tube and an RTP chamber. The solid metal-gettering material getters metal before the metal reaches the substrate within the processing zone of a the processing chamber. Polysilicon pellets and silicon carbide pellets are examples of types of solid metal-getting materials, although other materials may be used. A purge gas may be flow within the gap or the gap may be evacuated while the pellets lie within the gap. Limitations on shapes and sizes of the pellets and purge gas flow rate are determined by the size of the gap.

Processing chamber for processing semiconductor substrates

A diffusivity and a solubility of dopant atoms are increased within a semiconductor wafer (30). A portion (36) of the semiconductor wafer (30) is disrupted by a technique of ion implantation thereby forming a defect layer (36). A predeposition layer (37) is formed by placing the semiconductor wafer (30) in a predeposition furnace. The defect layer (36) has a large number of point defects in a semiconductor crystal lattice which accept dopant atoms in excess of their solid solubility limit. The point defects increase the diffusivity and solubility of the dopant atoms thereby increasing a junction depth and surface concentration in subsequent high temperature diffusion steps.

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Tempe, AZ, United States of America

Herng-Der Chiou